SmogRank / Episodes / United States

California, United States, December 2024

For 11 days, from 1 to 11 December 2024, 61 cities in the United States had PM2.5 at least twice their usual for the time of year. The worst reading was Visalia, California, United States: 64.8 µg/m³ on 4 December, about 3.8× its usual 17.0.

No cause namedWe have no fire or smoke records for these days, so we only say what the measurements show.
Cities reached61in 1 country
Days111 to 11 December 2024
Worst day5 December37 cities counted
Furthest above usual5.2×Fontana

Day by day

5 December 37 cities at twice their usual or more
South Lake TahoeCarson CityTruckeeRenoSpanish SpringsTracyHollisterFolsomRidgecrestGilroyAtascaderoLincolnPrunedaleSalinasSan Luis ObispoWatsonvilleArroyo GrandeNipomoDavisSeasideLive OakSunnyvaleOrcuttSanta CruzLancasterRedwood CityFillmoreSanta BarbaraGoletaLompocSanta PaulaSanta ClaritaSimi ValleyOxnardThousand OaksParadiseVictorvilleGlendoraSanta RosaWindsorSummerlin SouthSpring ValleyEnterpriseBanningLas VegasUkiahHendersonTemeculaReddingBoulder CityIndioPowayMesquiteBrawleyAshlandEl CentroGrants PassYumaTwin FallsComptonCalexicoHawthorneAltamontLong BeachModestoImperial BeachEl CajonStocktonMedfordRosevilleCarsonTorranceArden-ArcadeAnaheimFlorinYuba CitySan JoseInglewoodChicoRichmondGaltBerkeleyChula VistaOceansideFresnoBakersfieldHanfordMaderaTurlockSan DiegoLomitaCorcoranMantecaVacavilleLivermoreOaklandSacramentoSouth San FranciscoSan FranciscoWoodlandVisaliaMercedPleasantonSanta MonicaLos AngelesJurupa ValleySan RafaelLa Crescenta-MontroseBurbankClovisSan LeandroConcordRiversidePalo AltoLake ElsinoreVallejoMartinezAgouraPortervilleFontana
28 Nov1 Dec47101314
Every measured city in the area, coloured by its PM2.5 that day; a dark ring marks a city at twice its usual or more. Bars: cities counted each day, coloured by their median level. Choose a day or press play; without JavaScript, the days link to that day's world ranking.

How it spread

ChicoChico, 28 November: 29.3 µg/m³, 3.3× usualChico, 29 November: 24.1 µg/m³, 2.7× usualChico, 30 November: 20.3 µg/m³, 2.3× usualChico, 1 December: 28.1 µg/m³, 3.1× usualChico, 2 December: 25.8 µg/m³, 2.9× usualChico, 3 December: 24.4 µg/m³, 2.7× usualChico, 4 December: 27.2 µg/m³, 3.0× usualChico, 5 December: 25.0 µg/m³, 2.8× usualChico, 6 December: 24.1 µg/m³, 2.7× usualChico, 7 December: 28.3 µg/m³, 3.1× usualChico, 8 December: 10.8 µg/m³, 1.2× usualChico, 9 December: 11.7 µg/m³, 1.3× usualChico, 10 December: 24.4 µg/m³, 2.7× usualChico, 11 December: 22.5 µg/m³, 2.5× usualChico, 12 December: 9.1 µg/m³, 1.0× usualChico, 13 December: 3.5 µg/m³, 0.4× usualChico, 14 December: 3.7 µg/m³, 0.4× usualStocktonStockton, 28 November: 23.8 µg/m³, 1.7× usualStockton, 29 November: 36.5 µg/m³, 2.6× usualStockton, 30 November: 24.3 µg/m³, 1.7× usualStockton, 1 December: 27.1 µg/m³, 1.9× usualStockton, 2 December: 26.8 µg/m³, 1.9× usualStockton, 3 December: 36.2 µg/m³, 2.5× usualStockton, 4 December: 39.0 µg/m³, 2.7× usualStockton, 5 December: 36.7 µg/m³, 2.6× usualStockton, 6 December: no readingStockton, 7 December: no readingStockton, 8 December: no readingStockton, 9 December: no readingStockton, 10 December: no readingStockton, 11 December: no readingStockton, 12 December: no readingStockton, 13 December: 8.5 µg/m³, 0.6× usualStockton, 14 December: no readingArden-ArcadeArden-Arcade, 28 November: 19.6 µg/m³, 1.8× usualArden-Arcade, 29 November: 28.4 µg/m³, 2.6× usualArden-Arcade, 30 November: 22.3 µg/m³, 2.0× usualArden-Arcade, 1 December: 20.8 µg/m³, 1.9× usualArden-Arcade, 2 December: 24.0 µg/m³, 2.2× usualArden-Arcade, 3 December: 26.8 µg/m³, 2.4× usualArden-Arcade, 4 December: 27.0 µg/m³, 2.5× usualArden-Arcade, 5 December: 20.2 µg/m³, 1.8× usualArden-Arcade, 6 December: 24.3 µg/m³, 2.2× usualArden-Arcade, 7 December: 31.4 µg/m³, 2.9× usualArden-Arcade, 8 December: 15.8 µg/m³, 1.4× usualArden-Arcade, 9 December: 11.8 µg/m³, 1.1× usualArden-Arcade, 10 December: 24.0 µg/m³, 2.2× usualArden-Arcade, 11 December: 25.9 µg/m³, 2.4× usualArden-Arcade, 12 December: 12.5 µg/m³, 1.1× usualArden-Arcade, 13 December: 2.3 µg/m³, 0.2× usualArden-Arcade, 14 December: 2.8 µg/m³, 0.3× usualFlorinFlorin, 28 November: 19.3 µg/m³, 1.3× usualFlorin, 29 November: 26.9 µg/m³, 1.9× usualFlorin, 30 November: 32.8 µg/m³, 2.3× usualFlorin, 1 December: 32.5 µg/m³, 2.2× usualFlorin, 2 December: 32.5 µg/m³, 2.2× usualFlorin, 3 December: 30.5 µg/m³, 2.1× usualFlorin, 4 December: 28.4 µg/m³, 2.0× usualFlorin, 5 December: 28.6 µg/m³, 2.0× usualFlorin, 6 December: 34.0 µg/m³, 2.3× usualFlorin, 7 December: 44.1 µg/m³, 3.0× usualFlorin, 8 December: 30.4 µg/m³, 2.1× usualFlorin, 9 December: 21.2 µg/m³, 1.5× usualFlorin, 10 December: 29.8 µg/m³, 2.1× usualFlorin, 11 December: 37.8 µg/m³, 2.6× usualFlorin, 12 December: 26.7 µg/m³, 1.8× usualFlorin, 13 December: 12.9 µg/m³, 0.9× usualFlorin, 14 December: 1.7 µg/m³, 0.1× usualVisaliaVisalia, 28 November: 21.7 µg/m³, 1.3× usualVisalia, 29 November: 20.4 µg/m³, 1.2× usualVisalia, 30 November: 22.4 µg/m³, 1.3× usualVisalia, 1 December: 39.8 µg/m³, 2.3× usualVisalia, 2 December: 41.0 µg/m³, 2.4× usualVisalia, 3 December: 58.3 µg/m³, 3.4× usualVisalia, 4 December: 64.8 µg/m³, 3.8× usualVisalia, 5 December: 62.2 µg/m³, 3.7× usualVisalia, 6 December: no readingVisalia, 7 December: no readingVisalia, 8 December: no readingVisalia, 9 December: no readingVisalia, 10 December: no readingVisalia, 11 December: no readingVisalia, 12 December: no readingVisalia, 13 December: 14.1 µg/m³, 0.8× usualVisalia, 14 December: no readingBakersfieldBakersfield, 28 November: 17.1 µg/m³, 0.9× usualBakersfield, 29 November: 24.0 µg/m³, 1.3× usualBakersfield, 30 November: 36.8 µg/m³, 2.0× usualBakersfield, 1 December: 44.4 µg/m³, 2.4× usualBakersfield, 2 December: 49.7 µg/m³, 2.7× usualBakersfield, 3 December: 49.5 µg/m³, 2.7× usualBakersfield, 4 December: 52.2 µg/m³, 2.8× usualBakersfield, 5 December: 57.7 µg/m³, 3.1× usualBakersfield, 6 December: 59.5 µg/m³, 3.2× usualBakersfield, 7 December: 61.0 µg/m³, 3.3× usualBakersfield, 8 December: 58.8 µg/m³, 3.2× usualBakersfield, 9 December: 45.6 µg/m³, 2.5× usualBakersfield, 10 December: 26.6 µg/m³, 1.4× usualBakersfield, 11 December: 34.9 µg/m³, 1.9× usualBakersfield, 12 December: 25.2 µg/m³, 1.4× usualBakersfield, 13 December: 14.6 µg/m³, 0.8× usualBakersfield, 14 December: 6.7 µg/m³, 0.4× usualPortervillePorterville, 28 November: 17.1 µg/m³, 1.5× usualPorterville, 29 November: 16.1 µg/m³, 1.4× usualPorterville, 30 November: 21.7 µg/m³, 1.9× usualPorterville, 1 December: 34.2 µg/m³, 3.1× usualPorterville, 2 December: 36.8 µg/m³, 3.3× usualPorterville, 3 December: 47.0 µg/m³, 4.2× usualPorterville, 4 December: 45.2 µg/m³, 4.0× usualPorterville, 5 December: 51.5 µg/m³, 4.6× usualPorterville, 6 December: 54.8 µg/m³, 4.9× usualPorterville, 7 December: 53.2 µg/m³, 4.8× usualPorterville, 8 December: 54.2 µg/m³, 4.8× usualPorterville, 9 December: 33.1 µg/m³, 3.0× usualPorterville, 10 December: 20.9 µg/m³, 1.9× usualPorterville, 11 December: 22.2 µg/m³, 2.0× usualPorterville, 12 December: 11.9 µg/m³, 1.1× usualPorterville, 13 December: 9.0 µg/m³, 0.8× usualPorterville, 14 December: 6.7 µg/m³, 0.6× usualHanfordHanford, 28 November: 14.5 µg/m³, 0.9× usualHanford, 29 November: 19.5 µg/m³, 1.2× usualHanford, 30 November: 26.9 µg/m³, 1.7× usualHanford, 1 December: 34.6 µg/m³, 2.2× usualHanford, 2 December: 40.0 µg/m³, 2.5× usualHanford, 3 December: 47.5 µg/m³, 3.0× usualHanford, 4 December: 52.3 µg/m³, 3.3× usualHanford, 5 December: 53.8 µg/m³, 3.4× usualHanford, 6 December: 49.0 µg/m³, 3.1× usualHanford, 7 December: 45.0 µg/m³, 2.8× usualHanford, 8 December: 38.5 µg/m³, 2.4× usualHanford, 9 December: 31.8 µg/m³, 2.0× usualHanford, 10 December: 32.0 µg/m³, 2.0× usualHanford, 11 December: 31.7 µg/m³, 2.0× usualHanford, 12 December: 21.1 µg/m³, 1.3× usualHanford, 13 December: 16.0 µg/m³, 1.0× usualHanford, 14 December: 6.4 µg/m³, 0.4× usualTurlockTurlock, 28 November: 16.2 µg/m³, 1.2× usualTurlock, 29 November: 24.4 µg/m³, 1.8× usualTurlock, 30 November: 22.4 µg/m³, 1.7× usualTurlock, 1 December: 29.7 µg/m³, 2.2× usualTurlock, 2 December: 23.0 µg/m³, 1.7× usualTurlock, 3 December: 32.0 µg/m³, 2.4× usualTurlock, 4 December: 36.8 µg/m³, 2.7× usualTurlock, 5 December: 40.1 µg/m³, 3.0× usualTurlock, 6 December: 42.1 µg/m³, 3.1× usualTurlock, 7 December: 46.5 µg/m³, 3.5× usualTurlock, 8 December: 31.1 µg/m³, 2.3× usualTurlock, 9 December: 18.8 µg/m³, 1.4× usualTurlock, 10 December: 27.3 µg/m³, 2.0× usualTurlock, 11 December: 27.9 µg/m³, 2.1× usualTurlock, 12 December: 21.7 µg/m³, 1.6× usualTurlock, 13 December: 13.6 µg/m³, 1.0× usualTurlock, 14 December: 4.9 µg/m³, 0.4× usualMantecaManteca, 28 November: 14.5 µg/m³, 1.2× usualManteca, 29 November: 18.1 µg/m³, 1.5× usualManteca, 30 November: 24.0 µg/m³, 2.0× usualManteca, 1 December: 30.2 µg/m³, 2.5× usualManteca, 2 December: 19.4 µg/m³, 1.6× usualManteca, 3 December: 30.9 µg/m³, 2.5× usualManteca, 4 December: 31.1 µg/m³, 2.5× usualManteca, 5 December: 34.5 µg/m³, 2.8× usualManteca, 6 December: 35.4 µg/m³, 2.9× usualManteca, 7 December: 44.0 µg/m³, 3.6× usualManteca, 8 December: 25.1 µg/m³, 2.0× usualManteca, 9 December: 18.2 µg/m³, 1.5× usualManteca, 10 December: 28.3 µg/m³, 2.3× usualManteca, 11 December: 33.6 µg/m³, 2.7× usualManteca, 12 December: 25.7 µg/m³, 2.1× usualManteca, 13 December: 11.3 µg/m³, 0.9× usualManteca, 14 December: 6.8 µg/m³, 0.6× usualModestoModesto, 28 November: 13.4 µg/m³, 0.9× usualModesto, 29 November: 29.7 µg/m³, 2.0× usualModesto, 30 November: 24.0 µg/m³, 1.6× usualModesto, 1 December: 34.0 µg/m³, 2.3× usualModesto, 2 December: 25.5 µg/m³, 1.7× usualModesto, 3 December: 33.1 µg/m³, 2.3× usualModesto, 4 December: 38.8 µg/m³, 2.6× usualModesto, 5 December: 36.4 µg/m³, 2.5× usualModesto, 6 December: no readingModesto, 7 December: no readingModesto, 8 December: no readingModesto, 9 December: no readingModesto, 10 December: no readingModesto, 11 December: no readingModesto, 12 December: no readingModesto, 13 December: 11.2 µg/m³, 0.8× usualModesto, 14 December: no readingRosevilleRoseville, 28 November: 9.7 µg/m³, 1.0× usualRoseville, 29 November: 13.5 µg/m³, 1.4× usualRoseville, 30 November: 19.7 µg/m³, 2.0× usualRoseville, 1 December: 26.3 µg/m³, 2.7× usualRoseville, 2 December: 19.1 µg/m³, 2.0× usualRoseville, 3 December: 17.1 µg/m³, 1.8× usualRoseville, 4 December: 14.1 µg/m³, 1.5× usualRoseville, 5 December: 14.8 µg/m³, 1.5× usualRoseville, 6 December: no readingRoseville, 7 December: no readingRoseville, 8 December: no readingRoseville, 9 December: no readingRoseville, 10 December: no readingRoseville, 11 December: no readingRoseville, 12 December: no readingRoseville, 13 December: 3.8 µg/m³, 0.4× usualRoseville, 14 December: no readingJurupa ValleyJurupa Valley, 28 November: 7.0 µg/m³, 0.5× usualJurupa Valley, 29 November: 8.1 µg/m³, 0.6× usualJurupa Valley, 30 November: 13.5 µg/m³, 0.9× usualJurupa Valley, 1 December: 21.0 µg/m³, 1.4× usualJurupa Valley, 2 December: 29.7 µg/m³, 2.0× usualJurupa Valley, 3 December: 33.1 µg/m³, 2.3× usualJurupa Valley, 4 December: 42.4 µg/m³, 2.9× usualJurupa Valley, 5 December: 58.0 µg/m³, 4.0× usualJurupa Valley, 6 December: 21.2 µg/m³, 1.5× usualJurupa Valley, 7 December: 14.3 µg/m³, 1.0× usualJurupa Valley, 8 December: 23.9 µg/m³, 1.6× usualJurupa Valley, 9 December: 21.4 µg/m³, 1.5× usualJurupa Valley, 10 December: 4.0 µg/m³, 0.3× usualJurupa Valley, 11 December: 11.6 µg/m³, 0.8× usualJurupa Valley, 12 December: 14.4 µg/m³, 1.0× usualJurupa Valley, 13 December: 16.4 µg/m³, 1.1× usualJurupa Valley, 14 December: 20.2 µg/m³, 1.4× usualFresnoFresno, 28 November: 17.8 µg/m³, 1.0× usualFresno, 29 November: 20.7 µg/m³, 1.2× usualFresno, 30 November: 23.7 µg/m³, 1.3× usualFresno, 1 December: 31.3 µg/m³, 1.7× usualFresno, 2 December: 38.4 µg/m³, 2.1× usualFresno, 3 December: 44.8 µg/m³, 2.5× usualFresno, 4 December: 49.0 µg/m³, 2.7× usualFresno, 5 December: 54.9 µg/m³, 3.1× usualFresno, 6 December: 57.1 µg/m³, 3.2× usualFresno, 7 December: 54.5 µg/m³, 3.0× usualFresno, 8 December: 42.8 µg/m³, 2.4× usualFresno, 9 December: 39.2 µg/m³, 2.2× usualFresno, 10 December: 32.3 µg/m³, 1.8× usualFresno, 11 December: 36.7 µg/m³, 2.0× usualFresno, 12 December: 20.7 µg/m³, 1.2× usualFresno, 13 December: 9.5 µg/m³, 0.5× usualFresno, 14 December: 4.4 µg/m³, 0.2× usualClovisClovis, 28 November: 14.6 µg/m³, 1.2× usualClovis, 29 November: 16.0 µg/m³, 1.3× usualClovis, 30 November: 20.2 µg/m³, 1.7× usualClovis, 1 December: 24.7 µg/m³, 2.0× usualClovis, 2 December: 28.7 µg/m³, 2.4× usualClovis, 3 December: 40.1 µg/m³, 3.3× usualClovis, 4 December: 40.4 µg/m³, 3.3× usualClovis, 5 December: 46.4 µg/m³, 3.8× usualClovis, 6 December: 51.3 µg/m³, 4.2× usualClovis, 7 December: 49.7 µg/m³, 4.1× usualClovis, 8 December: 41.0 µg/m³, 3.4× usualClovis, 9 December: 43.4 µg/m³, 3.6× usualClovis, 10 December: 32.6 µg/m³, 2.7× usualClovis, 11 December: 29.2 µg/m³, 2.4× usualClovis, 12 December: 19.8 µg/m³, 1.6× usualClovis, 13 December: 10.2 µg/m³, 0.8× usualClovis, 14 December: 6.0 µg/m³, 0.5× usualSacramentoSacramento, 28 November: 11.9 µg/m³, 1.2× usualSacramento, 29 November: 12.3 µg/m³, 1.3× usualSacramento, 30 November: 22.5 µg/m³, 2.3× usualSacramento, 1 December: 20.6 µg/m³, 2.1× usualSacramento, 2 December: 25.8 µg/m³, 2.7× usualSacramento, 3 December: 26.2 µg/m³, 2.7× usualSacramento, 4 December: 26.4 µg/m³, 2.8× usualSacramento, 5 December: 24.1 µg/m³, 2.5× usualSacramento, 6 December: 24.9 µg/m³, 2.6× usualSacramento, 7 December: 35.3 µg/m³, 3.7× usualSacramento, 8 December: 17.0 µg/m³, 1.8× usualSacramento, 9 December: 11.5 µg/m³, 1.2× usualSacramento, 10 December: 24.4 µg/m³, 2.5× usualSacramento, 11 December: 26.2 µg/m³, 2.7× usualSacramento, 12 December: 16.1 µg/m³, 1.7× usualSacramento, 13 December: 5.0 µg/m³, 0.5× usualSacramento, 14 December: 3.8 µg/m³, 0.4× usualMedfordMedford, 28 November: 20.1 µg/m³, 1.7× usualMedford, 29 November: 16.6 µg/m³, 1.4× usualMedford, 30 November: 15.3 µg/m³, 1.3× usualMedford, 1 December: 17.3 µg/m³, 1.5× usualMedford, 2 December: 27.7 µg/m³, 2.4× usualMedford, 3 December: 30.3 µg/m³, 2.6× usualMedford, 4 December: 30.8 µg/m³, 2.7× usualMedford, 5 December: 24.8 µg/m³, 2.1× usualMedford, 6 December: 24.7 µg/m³, 2.1× usualMedford, 7 December: 21.1 µg/m³, 1.8× usualMedford, 8 December: 9.4 µg/m³, 0.8× usualMedford, 9 December: 16.3 µg/m³, 1.4× usualMedford, 10 December: 24.6 µg/m³, 2.1× usualMedford, 11 December: 20.0 µg/m³, 1.7× usualMedford, 12 December: 8.1 µg/m³, 0.7× usualMedford, 13 December: 8.5 µg/m³, 0.7× usualMedford, 14 December: 5.1 µg/m³, 0.4× usualRiversideRiverside, 28 November: 4.2 µg/m³, 0.3× usualRiverside, 29 November: 3.8 µg/m³, 0.3× usualRiverside, 30 November: 7.3 µg/m³, 0.6× usualRiverside, 1 December: 13.2 µg/m³, 1.1× usualRiverside, 2 December: 23.2 µg/m³, 1.9× usualRiverside, 3 December: 25.2 µg/m³, 2.1× usualRiverside, 4 December: 35.8 µg/m³, 2.9× usualRiverside, 5 December: 53.5 µg/m³, 4.4× usualRiverside, 6 December: 16.6 µg/m³, 1.4× usualRiverside, 7 December: 11.9 µg/m³, 1.0× usualRiverside, 8 December: 16.3 µg/m³, 1.3× usualRiverside, 9 December: 18.0 µg/m³, 1.5× usualRiverside, 10 December: 3.3 µg/m³, 0.3× usualRiverside, 11 December: 6.2 µg/m³, 0.5× usualRiverside, 12 December: 11.3 µg/m³, 0.9× usualRiverside, 13 December: 15.8 µg/m³, 1.3× usualRiverside, 14 December: 16.2 µg/m³, 1.3× usualFontanaFontana, 28 November: 12.9 µg/m³, 1.3× usualFontana, 29 November: 7.6 µg/m³, 0.8× usualFontana, 30 November: 7.8 µg/m³, 0.8× usualFontana, 1 December: 13.7 µg/m³, 1.4× usualFontana, 2 December: 21.5 µg/m³, 2.2× usualFontana, 3 December: 27.6 µg/m³, 2.8× usualFontana, 4 December: 38.9 µg/m³, 3.9× usualFontana, 5 December: 51.7 µg/m³, 5.2× usualFontana, 6 December: 14.5 µg/m³, 1.5× usualFontana, 7 December: 8.2 µg/m³, 0.8× usualFontana, 8 December: 12.0 µg/m³, 1.2× usualFontana, 9 December: 14.4 µg/m³, 1.4× usualFontana, 10 December: 5.5 µg/m³, 0.6× usualFontana, 11 December: 10.4 µg/m³, 1.0× usualFontana, 12 December: 10.9 µg/m³, 1.1× usualFontana, 13 December: 16.9 µg/m³, 1.7× usualFontana, 14 December: 12.6 µg/m³, 1.3× usualCorcoranCorcoran, 28 November: 12.7 µg/m³, 1.0× usualCorcoran, 29 November: 17.4 µg/m³, 1.3× usualCorcoran, 30 November: 21.4 µg/m³, 1.6× usualCorcoran, 1 December: 30.0 µg/m³, 2.3× usualCorcoran, 2 December: 28.4 µg/m³, 2.2× usualCorcoran, 3 December: 34.4 µg/m³, 2.6× usualCorcoran, 4 December: 43.5 µg/m³, 3.3× usualCorcoran, 5 December: 48.1 µg/m³, 3.6× usualCorcoran, 6 December: 39.7 µg/m³, 3.0× usualCorcoran, 7 December: 40.4 µg/m³, 3.1× usualCorcoran, 8 December: 29.3 µg/m³, 2.2× usualCorcoran, 9 December: 26.0 µg/m³, 2.0× usualCorcoran, 10 December: 28.0 µg/m³, 2.1× usualCorcoran, 11 December: 26.3 µg/m³, 2.0× usualCorcoran, 12 December: 17.8 µg/m³, 1.3× usualCorcoran, 13 December: 12.0 µg/m³, 0.9× usualCorcoran, 14 December: 4.9 µg/m³, 0.4× usualMaderaMadera, 28 November: 13.3 µg/m³, 1.0× usualMadera, 29 November: 19.5 µg/m³, 1.5× usualMadera, 30 November: 23.2 µg/m³, 1.8× usualMadera, 1 December: 24.8 µg/m³, 1.9× usualMadera, 2 December: 19.9 µg/m³, 1.5× usualMadera, 3 December: 33.9 µg/m³, 2.6× usualMadera, 4 December: 35.0 µg/m³, 2.7× usualMadera, 5 December: 41.8 µg/m³, 3.2× usualMadera, 6 December: 44.2 µg/m³, 3.4× usualMadera, 7 December: 46.4 µg/m³, 3.5× usualMadera, 8 December: 38.1 µg/m³, 2.9× usualMadera, 9 December: 33.1 µg/m³, 2.5× usualMadera, 10 December: 30.6 µg/m³, 2.3× usualMadera, 11 December: 25.2 µg/m³, 1.9× usualMadera, 12 December: 19.7 µg/m³, 1.5× usualMadera, 13 December: 10.4 µg/m³, 0.8× usualMadera, 14 December: 5.2 µg/m³, 0.4× usualWoodlandWoodland, 28 November: 13.7 µg/m³, 1.2× usualWoodland, 29 November: 12.5 µg/m³, 1.1× usualWoodland, 30 November: 20.8 µg/m³, 1.8× usualWoodland, 1 December: 19.0 µg/m³, 1.7× usualWoodland, 2 December: 22.5 µg/m³, 2.0× usualWoodland, 3 December: 29.7 µg/m³, 2.6× usualWoodland, 4 December: 24.3 µg/m³, 2.2× usualWoodland, 5 December: 25.3 µg/m³, 2.2× usualWoodland, 6 December: 33.8 µg/m³, 3.0× usualWoodland, 7 December: 42.5 µg/m³, 3.8× usualWoodland, 8 December: 11.8 µg/m³, 1.0× usualWoodland, 9 December: 9.4 µg/m³, 0.8× usualWoodland, 10 December: 28.5 µg/m³, 2.5× usualWoodland, 11 December: 28.4 µg/m³, 2.5× usualWoodland, 12 December: 22.5 µg/m³, 2.0× usualWoodland, 13 December: 9.7 µg/m³, 0.9× usualWoodland, 14 December: 6.0 µg/m³, 0.5× usualMercedMerced, 28 November: 13.2 µg/m³, 1.0× usualMerced, 29 November: 17.2 µg/m³, 1.3× usualMerced, 30 November: 24.3 µg/m³, 1.8× usualMerced, 1 December: 26.8 µg/m³, 2.0× usualMerced, 2 December: 22.6 µg/m³, 1.7× usualMerced, 3 December: 26.8 µg/m³, 2.0× usualMerced, 4 December: 37.4 µg/m³, 2.8× usualMerced, 5 December: 41.3 µg/m³, 3.1× usualMerced, 6 December: 42.5 µg/m³, 3.2× usualMerced, 7 December: 51.5 µg/m³, 3.9× usualMerced, 8 December: 34.4 µg/m³, 2.6× usualMerced, 9 December: 24.0 µg/m³, 1.8× usualMerced, 10 December: 30.0 µg/m³, 2.3× usualMerced, 11 December: 25.6 µg/m³, 1.9× usualMerced, 12 December: 19.4 µg/m³, 1.5× usualMerced, 13 December: 14.0 µg/m³, 1.1× usualMerced, 14 December: 4.4 µg/m³, 0.3× usualLos AngelesLos Angeles, 28 November: 9.1 µg/m³, 0.8× usualLos Angeles, 29 November: 9.1 µg/m³, 0.8× usualLos Angeles, 30 November: 8.7 µg/m³, 0.8× usualLos Angeles, 1 December: 16.0 µg/m³, 1.4× usualLos Angeles, 2 December: 17.7 µg/m³, 1.6× usualLos Angeles, 3 December: 23.5 µg/m³, 2.1× usualLos Angeles, 4 December: 37.7 µg/m³, 3.3× usualLos Angeles, 5 December: 45.2 µg/m³, 4.0× usualLos Angeles, 6 December: 29.1 µg/m³, 2.6× usualLos Angeles, 7 December: 12.3 µg/m³, 1.1× usualLos Angeles, 8 December: 16.4 µg/m³, 1.5× usualLos Angeles, 9 December: 32.2 µg/m³, 2.8× usualLos Angeles, 10 December: 16.7 µg/m³, 1.5× usualLos Angeles, 11 December: 7.9 µg/m³, 0.7× usualLos Angeles, 12 December: 10.5 µg/m³, 0.9× usualLos Angeles, 13 December: 15.4 µg/m³, 1.4× usualLos Angeles, 14 December: 14.1 µg/m³, 1.2× usualBurbankBurbank, 28 November: 10.7 µg/m³, 1.0× usualBurbank, 29 November: 11.9 µg/m³, 1.1× usualBurbank, 30 November: 9.2 µg/m³, 0.9× usualBurbank, 1 December: 15.6 µg/m³, 1.5× usualBurbank, 2 December: 17.6 µg/m³, 1.7× usualBurbank, 3 December: 23.6 µg/m³, 2.2× usualBurbank, 4 December: 37.0 µg/m³, 3.5× usualBurbank, 5 December: 44.2 µg/m³, 4.2× usualBurbank, 6 December: 22.2 µg/m³, 2.1× usualBurbank, 7 December: 9.8 µg/m³, 0.9× usualBurbank, 8 December: 20.3 µg/m³, 1.9× usualBurbank, 9 December: 31.6 µg/m³, 3.0× usualBurbank, 10 December: 15.4 µg/m³, 1.5× usualBurbank, 11 December: 10.7 µg/m³, 1.0× usualBurbank, 12 December: 12.9 µg/m³, 1.2× usualBurbank, 13 December: 16.1 µg/m³, 1.5× usualBurbank, 14 December: 15.7 µg/m³, 1.5× usualPalo AltoPalo Alto, 28 November: 9.1 µg/m³, 1.0× usualPalo Alto, 29 November: 12.3 µg/m³, 1.3× usualPalo Alto, 30 November: 13.7 µg/m³, 1.5× usualPalo Alto, 1 December: 16.2 µg/m³, 1.8× usualPalo Alto, 2 December: 9.7 µg/m³, 1.1× usualPalo Alto, 3 December: 11.5 µg/m³, 1.3× usualPalo Alto, 4 December: 28.1 µg/m³, 3.1× usualPalo Alto, 5 December: 26.1 µg/m³, 2.8× usualPalo Alto, 6 December: 15.8 µg/m³, 1.7× usualPalo Alto, 7 December: 31.5 µg/m³, 3.4× usualPalo Alto, 8 December: 27.3 µg/m³, 3.0× usualPalo Alto, 9 December: 4.9 µg/m³, 0.5× usualPalo Alto, 10 December: 12.3 µg/m³, 1.3× usualPalo Alto, 11 December: 41.6 µg/m³, 4.5× usualPalo Alto, 12 December: 5.8 µg/m³, 0.6× usualPalo Alto, 13 December: 2.7 µg/m³, 0.3× usualPalo Alto, 14 December: 2.6 µg/m³, 0.3× usualAnaheimAnaheim, 28 November: no readingAnaheim, 29 November: no readingAnaheim, 30 November: no readingAnaheim, 1 December: no readingAnaheim, 2 December: no readingAnaheim, 3 December: no readingAnaheim, 4 December: 27.9 µg/m³, 2.1× usualAnaheim, 5 December: 40.2 µg/m³, 3.0× usualAnaheim, 6 December: 31.3 µg/m³, 2.4× usualAnaheim, 7 December: 29.1 µg/m³, 2.2× usualAnaheim, 8 December: 14.8 µg/m³, 1.1× usualAnaheim, 9 December: 18.8 µg/m³, 1.4× usualAnaheim, 10 December: 2.2 µg/m³, 0.2× usualAnaheim, 11 December: 9.1 µg/m³, 0.7× usualAnaheim, 12 December: 10.7 µg/m³, 0.8× usualAnaheim, 13 December: 12.8 µg/m³, 1.0× usualAnaheim, 14 December: 15.2 µg/m³, 1.2× usualCarsonCarson, 28 November: 18.7 µg/m³, 1.5× usualCarson, 29 November: 9.6 µg/m³, 0.8× usualCarson, 30 November: 9.9 µg/m³, 0.8× usualCarson, 1 December: 17.0 µg/m³, 1.4× usualCarson, 2 December: 20.0 µg/m³, 1.6× usualCarson, 3 December: 20.8 µg/m³, 1.7× usualCarson, 4 December: 29.1 µg/m³, 2.3× usualCarson, 5 December: 34.3 µg/m³, 2.8× usualCarson, 6 December: 29.2 µg/m³, 2.4× usualCarson, 7 December: 18.8 µg/m³, 1.5× usualCarson, 8 December: 23.3 µg/m³, 1.9× usualCarson, 9 December: 22.5 µg/m³, 1.8× usualCarson, 10 December: 19.7 µg/m³, 1.6× usualCarson, 11 December: 12.5 µg/m³, 1.0× usualCarson, 12 December: 11.4 µg/m³, 0.9× usualCarson, 13 December: 15.0 µg/m³, 1.2× usualCarson, 14 December: 14.0 µg/m³, 1.1× usualHawthorneHawthorne, 28 November: 16.5 µg/m³, 1.2× usualHawthorne, 29 November: 7.9 µg/m³, 0.6× usualHawthorne, 30 November: 9.9 µg/m³, 0.7× usualHawthorne, 1 December: 18.5 µg/m³, 1.3× usualHawthorne, 2 December: 22.3 µg/m³, 1.6× usualHawthorne, 3 December: 23.8 µg/m³, 1.7× usualHawthorne, 4 December: 29.7 µg/m³, 2.1× usualHawthorne, 5 December: 32.1 µg/m³, 2.3× usualHawthorne, 6 December: 32.5 µg/m³, 2.3× usualHawthorne, 7 December: 24.0 µg/m³, 1.7× usualHawthorne, 8 December: 26.3 µg/m³, 1.9× usualHawthorne, 9 December: 26.3 µg/m³, 1.9× usualHawthorne, 10 December: 23.1 µg/m³, 1.6× usualHawthorne, 11 December: 12.9 µg/m³, 0.9× usualHawthorne, 12 December: 12.8 µg/m³, 0.9× usualHawthorne, 13 December: 15.9 µg/m³, 1.1× usualHawthorne, 14 December: 16.2 µg/m³, 1.1× usualSan JoseSan Jose, 28 November: 14.1 µg/m³, 1.4× usualSan Jose, 29 November: 19.0 µg/m³, 1.8× usualSan Jose, 30 November: 15.2 µg/m³, 1.5× usualSan Jose, 1 December: 17.8 µg/m³, 1.7× usualSan Jose, 2 December: 16.1 µg/m³, 1.6× usualSan Jose, 3 December: 17.6 µg/m³, 1.7× usualSan Jose, 4 December: 25.3 µg/m³, 2.5× usualSan Jose, 5 December: 26.9 µg/m³, 2.6× usualSan Jose, 6 December: 20.4 µg/m³, 2.0× usualSan Jose, 7 December: 24.7 µg/m³, 2.4× usualSan Jose, 8 December: 32.3 µg/m³, 3.1× usualSan Jose, 9 December: 10.8 µg/m³, 1.0× usualSan Jose, 10 December: 14.7 µg/m³, 1.4× usualSan Jose, 11 December: 30.4 µg/m³, 3.0× usualSan Jose, 12 December: 9.7 µg/m³, 0.9× usualSan Jose, 13 December: 5.3 µg/m³, 0.5× usualSan Jose, 14 December: 8.7 µg/m³, 0.8× usualInglewoodInglewood, 28 November: 10.9 µg/m³, 1.0× usualInglewood, 29 November: 5.3 µg/m³, 0.5× usualInglewood, 30 November: 8.2 µg/m³, 0.8× usualInglewood, 1 December: 17.9 µg/m³, 1.7× usualInglewood, 2 December: 19.8 µg/m³, 1.9× usualInglewood, 3 December: 21.1 µg/m³, 2.0× usualInglewood, 4 December: 28.1 µg/m³, 2.7× usualInglewood, 5 December: 32.0 µg/m³, 3.1× usualInglewood, 6 December: 28.0 µg/m³, 2.7× usualInglewood, 7 December: 14.3 µg/m³, 1.4× usualInglewood, 8 December: 19.4 µg/m³, 1.9× usualInglewood, 9 December: 26.2 µg/m³, 2.5× usualInglewood, 10 December: 15.6 µg/m³, 1.5× usualInglewood, 11 December: 10.5 µg/m³, 1.0× usualInglewood, 12 December: 9.7 µg/m³, 0.9× usualInglewood, 13 December: 12.9 µg/m³, 1.2× usualInglewood, 14 December: 12.5 µg/m³, 1.2× usualSanta MonicaSanta Monica, 28 November: 6.9 µg/m³, 0.9× usualSanta Monica, 29 November: 4.1 µg/m³, 0.5× usualSanta Monica, 30 November: 4.8 µg/m³, 0.6× usualSanta Monica, 1 December: 11.7 µg/m³, 1.5× usualSanta Monica, 2 December: 12.5 µg/m³, 1.6× usualSanta Monica, 3 December: 17.4 µg/m³, 2.2× usualSanta Monica, 4 December: 27.9 µg/m³, 3.5× usualSanta Monica, 5 December: 32.0 µg/m³, 4.0× usualSanta Monica, 6 December: 20.3 µg/m³, 2.5× usualSanta Monica, 7 December: 8.3 µg/m³, 1.0× usualSanta Monica, 8 December: 14.9 µg/m³, 1.9× usualSanta Monica, 9 December: 27.6 µg/m³, 3.5× usualSanta Monica, 10 December: 6.9 µg/m³, 0.9× usualSanta Monica, 11 December: 8.6 µg/m³, 1.1× usualSanta Monica, 12 December: 8.1 µg/m³, 1.0× usualSanta Monica, 13 December: 10.4 µg/m³, 1.3× usualSanta Monica, 14 December: 8.4 µg/m³, 1.1× usualTorranceTorrance, 28 November: 16.6 µg/m³, 1.5× usualTorrance, 29 November: 8.5 µg/m³, 0.8× usualTorrance, 30 November: 9.8 µg/m³, 0.9× usualTorrance, 1 December: 15.5 µg/m³, 1.4× usualTorrance, 2 December: 16.9 µg/m³, 1.6× usualTorrance, 3 December: 18.9 µg/m³, 1.7× usualTorrance, 4 December: 28.9 µg/m³, 2.7× usualTorrance, 5 December: 31.3 µg/m³, 2.9× usualTorrance, 6 December: 28.9 µg/m³, 2.7× usualTorrance, 7 December: 14.4 µg/m³, 1.3× usualTorrance, 8 December: 19.8 µg/m³, 1.8× usualTorrance, 9 December: 20.8 µg/m³, 1.9× usualTorrance, 10 December: 14.6 µg/m³, 1.4× usualTorrance, 11 December: 11.6 µg/m³, 1.1× usualTorrance, 12 December: 10.2 µg/m³, 0.9× usualTorrance, 13 December: 12.9 µg/m³, 1.2× usualTorrance, 14 December: 11.0 µg/m³, 1.0× usualAgouraAgoura, 28 November: 5.0 µg/m³, 0.8× usualAgoura, 29 November: 6.8 µg/m³, 1.1× usualAgoura, 30 November: 6.3 µg/m³, 1.0× usualAgoura, 1 December: 7.3 µg/m³, 1.2× usualAgoura, 2 December: 7.7 µg/m³, 1.3× usualAgoura, 3 December: 13.7 µg/m³, 2.2× usualAgoura, 4 December: 29.6 µg/m³, 4.9× usualAgoura, 5 December: 27.7 µg/m³, 4.5× usualAgoura, 6 December: 4.8 µg/m³, 0.8× usualAgoura, 7 December: 5.5 µg/m³, 0.9× usualAgoura, 8 December: 13.7 µg/m³, 2.2× usualAgoura, 9 December: 20.5 µg/m³, 3.4× usualAgoura, 10 December: 4.2 µg/m³, 0.7× usualAgoura, 11 December: 6.2 µg/m³, 1.0× usualAgoura, 12 December: 7.7 µg/m³, 1.3× usualAgoura, 13 December: 14.3 µg/m³, 2.3× usualAgoura, 14 December: 8.5 µg/m³, 1.4× usualCalexicoCalexico, 28 November: 10.7 µg/m³, 0.8× usualCalexico, 29 November: 6.1 µg/m³, 0.5× usualCalexico, 30 November: 10.2 µg/m³, 0.8× usualCalexico, 1 December: 22.8 µg/m³, 1.8× usualCalexico, 2 December: 12.6 µg/m³, 1.0× usualCalexico, 3 December: 15.1 µg/m³, 1.2× usualCalexico, 4 December: 27.7 µg/m³, 2.2× usualCalexico, 5 December: 16.7 µg/m³, 1.3× usualCalexico, 6 December: no readingCalexico, 7 December: no readingCalexico, 8 December: no readingCalexico, 9 December: no readingCalexico, 10 December: no readingCalexico, 11 December: no readingCalexico, 12 December: no readingCalexico, 13 December: no readingCalexico, 14 December: no readingLake ElsinoreLake Elsinore, 28 November: 2.9 µg/m³, 0.5× usualLake Elsinore, 29 November: 1.9 µg/m³, 0.3× usualLake Elsinore, 30 November: 4.5 µg/m³, 0.8× usualLake Elsinore, 1 December: 4.7 µg/m³, 0.8× usualLake Elsinore, 2 December: 11.9 µg/m³, 2.0× usualLake Elsinore, 3 December: 15.3 µg/m³, 2.6× usualLake Elsinore, 4 December: 26.2 µg/m³, 4.4× usualLake Elsinore, 5 December: 27.3 µg/m³, 4.6× usualLake Elsinore, 6 December: 11.3 µg/m³, 1.9× usualLake Elsinore, 7 December: 5.2 µg/m³, 0.9× usualLake Elsinore, 8 December: 9.9 µg/m³, 1.7× usualLake Elsinore, 9 December: 11.2 µg/m³, 1.9× usualLake Elsinore, 10 December: 4.3 µg/m³, 0.7× usualLake Elsinore, 11 December: 6.8 µg/m³, 1.2× usualLake Elsinore, 12 December: 9.7 µg/m³, 1.6× usualLake Elsinore, 13 December: 11.8 µg/m³, 2.0× usualLake Elsinore, 14 December: 11.9 µg/m³, 2.0× usualLa Crescenta-Montro…La Crescenta-Montrose, 28 November: 4.1 µg/m³, 0.7× usualLa Crescenta-Montrose, 29 November: 5.1 µg/m³, 0.9× usualLa Crescenta-Montrose, 30 November: 5.5 µg/m³, 0.9× usualLa Crescenta-Montrose, 1 December: 8.2 µg/m³, 1.4× usualLa Crescenta-Montrose, 2 December: 10.5 µg/m³, 1.8× usualLa Crescenta-Montrose, 3 December: 18.6 µg/m³, 3.2× usualLa Crescenta-Montrose, 4 December: 25.0 µg/m³, 4.2× usualLa Crescenta-Montrose, 5 December: 15.2 µg/m³, 2.6× usualLa Crescenta-Montrose, 6 December: 3.5 µg/m³, 0.6× usualLa Crescenta-Montrose, 7 December: 4.3 µg/m³, 0.7× usualLa Crescenta-Montrose, 8 December: 9.6 µg/m³, 1.6× usualLa Crescenta-Montrose, 9 December: 11.1 µg/m³, 1.9× usualLa Crescenta-Montrose, 10 December: 5.4 µg/m³, 0.9× usualLa Crescenta-Montrose, 11 December: 14.7 µg/m³, 2.5× usualLa Crescenta-Montrose, 12 December: 9.7 µg/m³, 1.6× usualLa Crescenta-Montrose, 13 December: 8.3 µg/m³, 1.4× usualLa Crescenta-Montrose, 14 December: 7.1 µg/m³, 1.2× usualSan DiegoSan Diego, 28 November: 14.4 µg/m³, 1.4× usualSan Diego, 29 November: 6.4 µg/m³, 0.6× usualSan Diego, 30 November: 8.8 µg/m³, 0.9× usualSan Diego, 1 December: 13.2 µg/m³, 1.3× usualSan Diego, 2 December: 9.8 µg/m³, 1.0× usualSan Diego, 3 December: 14.8 µg/m³, 1.4× usualSan Diego, 4 December: 21.3 µg/m³, 2.1× usualSan Diego, 5 December: 29.5 µg/m³, 2.9× usualSan Diego, 6 December: 37.1 µg/m³, 3.6× usualSan Diego, 7 December: 9.3 µg/m³, 0.9× usualSan Diego, 8 December: 13.5 µg/m³, 1.3× usualSan Diego, 9 December: 23.0 µg/m³, 2.2× usualSan Diego, 10 December: 7.2 µg/m³, 0.7× usualSan Diego, 11 December: 6.7 µg/m³, 0.7× usualSan Diego, 12 December: 11.0 µg/m³, 1.1× usualSan Diego, 13 December: 11.2 µg/m³, 1.1× usualSan Diego, 14 December: 16.7 µg/m³, 1.6× usualComptonCompton, 28 November: 15.0 µg/m³, 0.9× usualCompton, 29 November: 11.1 µg/m³, 0.7× usualCompton, 30 November: 11.7 µg/m³, 0.7× usualCompton, 1 December: 19.1 µg/m³, 1.1× usualCompton, 2 December: 21.8 µg/m³, 1.3× usualCompton, 3 December: 19.6 µg/m³, 1.2× usualCompton, 4 December: 24.0 µg/m³, 1.4× usualCompton, 5 December: 36.7 µg/m³, 2.2× usualCompton, 6 December: 33.1 µg/m³, 2.0× usualCompton, 7 December: 33.4 µg/m³, 2.0× usualCompton, 8 December: 28.6 µg/m³, 1.7× usualCompton, 9 December: 23.5 µg/m³, 1.4× usualCompton, 10 December: 25.1 µg/m³, 1.5× usualCompton, 11 December: 12.6 µg/m³, 0.8× usualCompton, 12 December: 14.3 µg/m³, 0.9× usualCompton, 13 December: 16.8 µg/m³, 1.0× usualCompton, 14 December: 19.3 µg/m³, 1.2× usualLong BeachLong Beach, 28 November: 12.3 µg/m³, 1.0× usualLong Beach, 29 November: 10.2 µg/m³, 0.8× usualLong Beach, 30 November: 8.2 µg/m³, 0.7× usualLong Beach, 1 December: 17.5 µg/m³, 1.4× usualLong Beach, 2 December: 23.6 µg/m³, 1.9× usualLong Beach, 3 December: 16.6 µg/m³, 1.3× usualLong Beach, 4 December: 17.7 µg/m³, 1.4× usualLong Beach, 5 December: 33.2 µg/m³, 2.6× usualLong Beach, 6 December: 25.5 µg/m³, 2.0× usualLong Beach, 7 December: 25.4 µg/m³, 2.0× usualLong Beach, 8 December: 20.3 µg/m³, 1.6× usualLong Beach, 9 December: 16.3 µg/m³, 1.3× usualLong Beach, 10 December: 15.8 µg/m³, 1.3× usualLong Beach, 11 December: 11.8 µg/m³, 0.9× usualLong Beach, 12 December: 19.6 µg/m³, 1.6× usualLong Beach, 13 December: 12.2 µg/m³, 1.0× usualLong Beach, 14 December: 16.5 µg/m³, 1.3× usualLomitaLomita, 28 November: 14.4 µg/m³, 1.8× usualLomita, 29 November: 6.8 µg/m³, 0.8× usualLomita, 30 November: 7.3 µg/m³, 0.9× usualLomita, 1 December: 12.7 µg/m³, 1.6× usualLomita, 2 December: 15.8 µg/m³, 2.0× usualLomita, 3 December: 17.7 µg/m³, 2.2× usualLomita, 4 December: 24.3 µg/m³, 3.0× usualLomita, 5 December: 28.0 µg/m³, 3.5× usualLomita, 6 December: 28.8 µg/m³, 3.6× usualLomita, 7 December: 9.7 µg/m³, 1.2× usualLomita, 8 December: 17.6 µg/m³, 2.2× usualLomita, 9 December: 16.4 µg/m³, 2.0× usualLomita, 10 December: 8.5 µg/m³, 1.0× usualLomita, 11 December: 8.4 µg/m³, 1.0× usualLomita, 12 December: 8.5 µg/m³, 1.0× usualLomita, 13 December: 11.7 µg/m³, 1.4× usualLomita, 14 December: 8.1 µg/m³, 1.0× usualEl CajonEl Cajon, 28 November: 7.3 µg/m³, 0.8× usualEl Cajon, 29 November: 6.5 µg/m³, 0.7× usualEl Cajon, 30 November: 8.1 µg/m³, 0.8× usualEl Cajon, 1 December: 10.6 µg/m³, 1.1× usualEl Cajon, 2 December: 8.9 µg/m³, 0.9× usualEl Cajon, 3 December: 13.9 µg/m³, 1.4× usualEl Cajon, 4 December: 21.0 µg/m³, 2.2× usualEl Cajon, 5 December: 26.2 µg/m³, 2.7× usualEl Cajon, 6 December: 19.5 µg/m³, 2.0× usualEl Cajon, 7 December: 10.2 µg/m³, 1.1× usualEl Cajon, 8 December: 15.4 µg/m³, 1.6× usualEl Cajon, 9 December: 21.5 µg/m³, 2.2× usualEl Cajon, 10 December: 9.8 µg/m³, 1.0× usualEl Cajon, 11 December: 9.9 µg/m³, 1.0× usualEl Cajon, 12 December: 9.8 µg/m³, 1.0× usualEl Cajon, 13 December: 9.2 µg/m³, 1.0× usualEl Cajon, 14 December: 14.2 µg/m³, 1.5× usualOceansideOceanside, 28 November: 17.2 µg/m³, 2.2× usualOceanside, 29 November: 7.6 µg/m³, 1.0× usualOceanside, 30 November: 6.1 µg/m³, 0.8× usualOceanside, 1 December: 6.3 µg/m³, 0.8× usualOceanside, 2 December: 9.3 µg/m³, 1.2× usualOceanside, 3 December: 11.5 µg/m³, 1.4× usualOceanside, 4 December: 12.8 µg/m³, 1.6× usualOceanside, 5 December: 25.3 µg/m³, 3.2× usualOceanside, 6 December: 25.9 µg/m³, 3.2× usualOceanside, 7 December: 13.7 µg/m³, 1.7× usualOceanside, 8 December: 11.5 µg/m³, 1.4× usualOceanside, 9 December: 15.3 µg/m³, 1.9× usualOceanside, 10 December: 4.7 µg/m³, 0.6× usualOceanside, 11 December: 7.9 µg/m³, 1.0× usualOceanside, 12 December: 7.8 µg/m³, 1.0× usualOceanside, 13 December: 10.8 µg/m³, 1.4× usualOceanside, 14 December: 11.6 µg/m³, 1.5× usualImperial BeachImperial Beach, 28 November: 15.0 µg/m³, 0.9× usualImperial Beach, 29 November: 8.4 µg/m³, 0.5× usualImperial Beach, 30 November: 12.1 µg/m³, 0.7× usualImperial Beach, 1 December: 32.9 µg/m³, 2.0× usualImperial Beach, 2 December: 29.1 µg/m³, 1.7× usualImperial Beach, 3 December: 25.3 µg/m³, 1.5× usualImperial Beach, 4 December: 23.6 µg/m³, 1.4× usualImperial Beach, 5 December: 29.8 µg/m³, 1.8× usualImperial Beach, 6 December: 45.4 µg/m³, 2.7× usualImperial Beach, 7 December: 39.3 µg/m³, 2.4× usualImperial Beach, 8 December: 32.9 µg/m³, 2.0× usualImperial Beach, 9 December: 30.4 µg/m³, 1.8× usualImperial Beach, 10 December: 13.2 µg/m³, 0.8× usualImperial Beach, 11 December: 9.4 µg/m³, 0.6× usualImperial Beach, 12 December: 20.0 µg/m³, 1.2× usualImperial Beach, 13 December: 14.3 µg/m³, 0.9× usualImperial Beach, 14 December: 27.8 µg/m³, 1.7× usualChula VistaChula Vista, 28 November: 10.2 µg/m³, 1.1× usualChula Vista, 29 November: 6.0 µg/m³, 0.7× usualChula Vista, 30 November: 6.7 µg/m³, 0.7× usualChula Vista, 1 December: 14.8 µg/m³, 1.6× usualChula Vista, 2 December: 10.4 µg/m³, 1.1× usualChula Vista, 3 December: 16.1 µg/m³, 1.8× usualChula Vista, 4 December: 18.5 µg/m³, 2.0× usualChula Vista, 5 December: 24.5 µg/m³, 2.7× usualChula Vista, 6 December: 28.8 µg/m³, 3.2× usualChula Vista, 7 December: 8.1 µg/m³, 0.9× usualChula Vista, 8 December: 11.5 µg/m³, 1.3× usualChula Vista, 9 December: 23.9 µg/m³, 2.6× usualChula Vista, 10 December: 7.1 µg/m³, 0.8× usualChula Vista, 11 December: 6.4 µg/m³, 0.7× usualChula Vista, 12 December: 10.4 µg/m³, 1.1× usualChula Vista, 13 December: 9.8 µg/m³, 1.1× usualChula Vista, 14 December: 15.3 µg/m³, 1.7× usualVallejoVallejo, 28 November: 8.3 µg/m³, 1.0× usualVallejo, 29 November: 7.2 µg/m³, 0.9× usualVallejo, 30 November: 15.0 µg/m³, 1.9× usualVallejo, 1 December: 13.0 µg/m³, 1.6× usualVallejo, 2 December: 11.2 µg/m³, 1.4× usualVallejo, 3 December: 19.9 µg/m³, 2.5× usualVallejo, 4 December: 22.5 µg/m³, 2.8× usualVallejo, 5 December: 19.3 µg/m³, 2.4× usualVallejo, 6 December: 18.2 µg/m³, 2.3× usualVallejo, 7 December: 37.6 µg/m³, 4.7× usualVallejo, 8 December: 28.0 µg/m³, 3.5× usualVallejo, 9 December: no readingVallejo, 10 December: no readingVallejo, 11 December: 26.3 µg/m³, 3.3× usualVallejo, 12 December: 7.5 µg/m³, 0.9× usualVallejo, 13 December: 4.1 µg/m³, 0.5× usualVallejo, 14 December: 4.2 µg/m³, 0.5× usualMartinezMartinez, 28 November: 6.7 µg/m³, 0.9× usualMartinez, 29 November: 9.0 µg/m³, 1.2× usualMartinez, 30 November: 21.3 µg/m³, 2.8× usualMartinez, 1 December: 16.1 µg/m³, 2.1× usualMartinez, 2 December: 9.5 µg/m³, 1.3× usualMartinez, 3 December: no readingMartinez, 4 December: no readingMartinez, 5 December: no readingMartinez, 6 December: 16.0 µg/m³, 2.1× usualMartinez, 7 December: 37.1 µg/m³, 4.9× usualMartinez, 8 December: 23.0 µg/m³, 3.1× usualMartinez, 9 December: 8.0 µg/m³, 1.1× usualMartinez, 10 December: 24.7 µg/m³, 3.3× usualMartinez, 11 December: 31.0 µg/m³, 4.1× usualMartinez, 12 December: 11.3 µg/m³, 1.5× usualMartinez, 13 December: 5.7 µg/m³, 0.8× usualMartinez, 14 December: 6.1 µg/m³, 0.8× usualOaklandOakland, 28 November: 5.2 µg/m³, 0.5× usualOakland, 29 November: 7.4 µg/m³, 0.8× usualOakland, 30 November: 9.5 µg/m³, 1.0× usualOakland, 1 December: 11.8 µg/m³, 1.2× usualOakland, 2 December: 11.0 µg/m³, 1.1× usualOakland, 3 December: 16.0 µg/m³, 1.7× usualOakland, 4 December: 20.2 µg/m³, 2.1× usualOakland, 5 December: 18.8 µg/m³, 2.0× usualOakland, 6 December: 17.6 µg/m³, 1.8× usualOakland, 7 December: 35.5 µg/m³, 3.7× usualOakland, 8 December: 29.7 µg/m³, 3.1× usualOakland, 9 December: 6.7 µg/m³, 0.7× usualOakland, 10 December: 18.3 µg/m³, 1.9× usualOakland, 11 December: 26.3 µg/m³, 2.7× usualOakland, 12 December: 8.1 µg/m³, 0.8× usualOakland, 13 December: 3.8 µg/m³, 0.4× usualOakland, 14 December: 5.8 µg/m³, 0.6× usualBerkeleyBerkeley, 28 November: 8.4 µg/m³, 0.8× usualBerkeley, 29 November: 8.4 µg/m³, 0.8× usualBerkeley, 30 November: 11.8 µg/m³, 1.1× usualBerkeley, 1 December: 11.7 µg/m³, 1.1× usualBerkeley, 2 December: 13.2 µg/m³, 1.2× usualBerkeley, 3 December: 19.5 µg/m³, 1.8× usualBerkeley, 4 December: 21.4 µg/m³, 1.9× usualBerkeley, 5 December: 19.2 µg/m³, 1.7× usualBerkeley, 6 December: 18.0 µg/m³, 1.6× usualBerkeley, 7 December: 35.1 µg/m³, 3.2× usualBerkeley, 8 December: 30.0 µg/m³, 2.7× usualBerkeley, 9 December: 9.2 µg/m³, 0.8× usualBerkeley, 10 December: 20.0 µg/m³, 1.8× usualBerkeley, 11 December: 26.5 µg/m³, 2.4× usualBerkeley, 12 December: 11.2 µg/m³, 1.0× usualBerkeley, 13 December: 6.9 µg/m³, 0.6× usualBerkeley, 14 December: 9.3 µg/m³, 0.8× usualRichmondRichmond, 28 November: 8.8 µg/m³, 0.9× usualRichmond, 29 November: 6.8 µg/m³, 0.7× usualRichmond, 30 November: 13.8 µg/m³, 1.4× usualRichmond, 1 December: 8.9 µg/m³, 0.9× usualRichmond, 2 December: 8.7 µg/m³, 0.9× usualRichmond, 3 December: 13.3 µg/m³, 1.3× usualRichmond, 4 December: 17.1 µg/m³, 1.7× usualRichmond, 5 December: 13.8 µg/m³, 1.4× usualRichmond, 6 December: 13.0 µg/m³, 1.3× usualRichmond, 7 December: 32.3 µg/m³, 3.2× usualRichmond, 8 December: 25.1 µg/m³, 2.5× usualRichmond, 9 December: 6.5 µg/m³, 0.7× usualRichmond, 10 December: 20.9 µg/m³, 2.1× usualRichmond, 11 December: 23.1 µg/m³, 2.3× usualRichmond, 12 December: 7.5 µg/m³, 0.8× usualRichmond, 13 December: 10.0 µg/m³, 1.0× usualRichmond, 14 December: 8.2 µg/m³, 0.8× usualSan FranciscoSan Francisco, 28 November: no readingSan Francisco, 29 November: no readingSan Francisco, 30 November: no readingSan Francisco, 1 December: no readingSan Francisco, 2 December: no readingSan Francisco, 3 December: 10.8 µg/m³, 1.3× usualSan Francisco, 4 December: 15.3 µg/m³, 1.8× usualSan Francisco, 5 December: 11.9 µg/m³, 1.4× usualSan Francisco, 6 December: 13.8 µg/m³, 1.6× usualSan Francisco, 7 December: 32.2 µg/m³, 3.8× usualSan Francisco, 8 December: 23.5 µg/m³, 2.8× usualSan Francisco, 9 December: 6.9 µg/m³, 0.8× usualSan Francisco, 10 December: 16.5 µg/m³, 2.0× usualSan Francisco, 11 December: 20.9 µg/m³, 2.5× usualSan Francisco, 12 December: 7.5 µg/m³, 0.9× usualSan Francisco, 13 December: 3.8 µg/m³, 0.5× usualSan Francisco, 14 December: 6.0 µg/m³, 0.7× usualSouth San FranciscoSouth San Francisco, 28 November: 6.7 µg/m³, 0.8× usualSouth San Francisco, 29 November: 8.5 µg/m³, 1.1× usualSouth San Francisco, 30 November: 12.0 µg/m³, 1.5× usualSouth San Francisco, 1 December: 12.7 µg/m³, 1.6× usualSouth San Francisco, 2 December: 9.4 µg/m³, 1.2× usualSouth San Francisco, 3 December: 11.1 µg/m³, 1.4× usualSouth San Francisco, 4 December: 21.5 µg/m³, 2.7× usualSouth San Francisco, 5 December: 13.8 µg/m³, 1.7× usualSouth San Francisco, 6 December: 12.4 µg/m³, 1.6× usualSouth San Francisco, 7 December: 28.5 µg/m³, 3.6× usualSouth San Francisco, 8 December: 30.0 µg/m³, 3.8× usualSouth San Francisco, 9 December: 7.0 µg/m³, 0.9× usualSouth San Francisco, 10 December: 19.6 µg/m³, 2.5× usualSouth San Francisco, 11 December: 24.8 µg/m³, 3.1× usualSouth San Francisco, 12 December: 5.7 µg/m³, 0.7× usualSouth San Francisco, 13 December: 4.0 µg/m³, 0.5× usualSouth San Francisco, 14 December: 4.6 µg/m³, 0.6× usualSan RafaelSan Rafael, 28 November: 4.8 µg/m³, 0.7× usualSan Rafael, 29 November: 5.7 µg/m³, 0.9× usualSan Rafael, 30 November: 12.7 µg/m³, 1.9× usualSan Rafael, 1 December: 11.0 µg/m³, 1.7× usualSan Rafael, 2 December: 6.4 µg/m³, 1.0× usualSan Rafael, 3 December: 10.3 µg/m³, 1.6× usualSan Rafael, 4 December: 13.0 µg/m³, 2.0× usualSan Rafael, 5 December: 9.1 µg/m³, 1.4× usualSan Rafael, 6 December: 10.3 µg/m³, 1.6× usualSan Rafael, 7 December: 27.9 µg/m³, 4.2× usualSan Rafael, 8 December: 18.4 µg/m³, 2.8× usualSan Rafael, 9 December: 5.6 µg/m³, 0.8× usualSan Rafael, 10 December: 20.8 µg/m³, 3.2× usualSan Rafael, 11 December: 22.0 µg/m³, 3.3× usualSan Rafael, 12 December: 6.7 µg/m³, 1.0× usualSan Rafael, 13 December: 5.5 µg/m³, 0.8× usualSan Rafael, 14 December: no readingSan LeandroSan Leandro, 28 November: 2.9 µg/m³, 0.4× usualSan Leandro, 29 November: 4.6 µg/m³, 0.7× usualSan Leandro, 30 November: 8.8 µg/m³, 1.4× usualSan Leandro, 1 December: 7.7 µg/m³, 1.2× usualSan Leandro, 2 December: 7.5 µg/m³, 1.2× usualSan Leandro, 3 December: 9.2 µg/m³, 1.4× usualSan Leandro, 4 December: 15.0 µg/m³, 2.3× usualSan Leandro, 5 December: 16.5 µg/m³, 2.5× usualSan Leandro, 6 December: 11.6 µg/m³, 1.8× usualSan Leandro, 7 December: 27.7 µg/m³, 4.3× usualSan Leandro, 8 December: 20.3 µg/m³, 3.1× usualSan Leandro, 9 December: 3.6 µg/m³, 0.6× usualSan Leandro, 10 December: 14.5 µg/m³, 2.2× usualSan Leandro, 11 December: 24.5 µg/m³, 3.8× usualSan Leandro, 12 December: 6.7 µg/m³, 1.0× usualSan Leandro, 13 December: 3.0 µg/m³, 0.5× usualSan Leandro, 14 December: 5.1 µg/m³, 0.8× usualConcordConcord, 28 November: 4.8 µg/m³, 0.8× usualConcord, 29 November: no readingConcord, 30 November: no readingConcord, 1 December: no readingConcord, 2 December: no readingConcord, 3 December: 10.2 µg/m³, 1.7× usualConcord, 4 December: 13.1 µg/m³, 2.1× usualConcord, 5 December: 10.3 µg/m³, 1.7× usualConcord, 6 December: 9.7 µg/m³, 1.6× usualConcord, 7 December: 26.5 µg/m³, 4.3× usualConcord, 8 December: 14.6 µg/m³, 2.4× usualConcord, 9 December: 2.8 µg/m³, 0.5× usualConcord, 10 December: 18.8 µg/m³, 3.1× usualConcord, 11 December: 25.4 µg/m³, 4.2× usualConcord, 12 December: 5.8 µg/m³, 1.0× usualConcord, 13 December: 1.8 µg/m³, 0.3× usualConcord, 14 December: 3.3 µg/m³, 0.5× usualGaltGalt, 28 November: 6.7 µg/m³, 0.8× usualGalt, 29 November: 12.1 µg/m³, 1.5× usualGalt, 30 November: 18.3 µg/m³, 2.2× usualGalt, 1 December: 15.3 µg/m³, 1.8× usualGalt, 2 December: no readingGalt, 3 December: 17.8 µg/m³, 2.1× usualGalt, 4 December: 16.6 µg/m³, 2.0× usualGalt, 5 December: 15.8 µg/m³, 1.9× usualGalt, 6 December: 21.5 µg/m³, 2.6× usualGalt, 7 December: 26.5 µg/m³, 3.2× usualGalt, 8 December: 12.3 µg/m³, 1.5× usualGalt, 9 December: 10.3 µg/m³, 1.2× usualGalt, 10 December: 17.0 µg/m³, 2.0× usualGalt, 11 December: 19.7 µg/m³, 2.4× usualGalt, 12 December: 17.2 µg/m³, 2.1× usualGalt, 13 December: 7.6 µg/m³, 0.9× usualGalt, 14 December: 3.8 µg/m³, 0.5× usualYuba CityYuba City, 28 November: 12.7 µg/m³, 1.5× usualYuba City, 29 November: 14.2 µg/m³, 1.7× usualYuba City, 30 November: 20.9 µg/m³, 2.4× usualYuba City, 1 December: 22.1 µg/m³, 2.6× usualYuba City, 2 December: 23.3 µg/m³, 2.7× usualYuba City, 3 December: 21.6 µg/m³, 2.5× usualYuba City, 4 December: 23.5 µg/m³, 2.7× usualYuba City, 5 December: 22.0 µg/m³, 2.6× usualYuba City, 6 December: 22.5 µg/m³, 2.6× usualYuba City, 7 December: 26.3 µg/m³, 3.1× usualYuba City, 8 December: 8.8 µg/m³, 1.0× usualYuba City, 9 December: no readingYuba City, 10 December: no readingYuba City, 11 December: no readingYuba City, 12 December: no readingYuba City, 13 December: no readingYuba City, 14 December: no readingPleasantonPleasanton, 28 November: 4.2 µg/m³, 0.6× usualPleasanton, 29 November: 6.7 µg/m³, 1.0× usualPleasanton, 30 November: 9.1 µg/m³, 1.3× usualPleasanton, 1 December: 11.4 µg/m³, 1.7× usualPleasanton, 2 December: 7.5 µg/m³, 1.1× usualPleasanton, 3 December: 9.0 µg/m³, 1.3× usualPleasanton, 4 December: 13.6 µg/m³, 2.0× usualPleasanton, 5 December: 12.7 µg/m³, 1.9× usualPleasanton, 6 December: 9.6 µg/m³, 1.4× usualPleasanton, 7 December: 22.0 µg/m³, 3.2× usualPleasanton, 8 December: 21.9 µg/m³, 3.2× usualPleasanton, 9 December: 4.0 µg/m³, 0.6× usualPleasanton, 10 December: 16.1 µg/m³, 2.4× usualPleasanton, 11 December: 27.1 µg/m³, 4.0× usualPleasanton, 12 December: 7.0 µg/m³, 1.0× usualPleasanton, 13 December: 1.8 µg/m³, 0.3× usualPleasanton, 14 December: 3.5 µg/m³, 0.5× usualVacavilleVacaville, 28 November: 8.4 µg/m³, 1.2× usualVacaville, 29 November: 9.4 µg/m³, 1.3× usualVacaville, 30 November: 17.0 µg/m³, 2.3× usualVacaville, 1 December: 14.4 µg/m³, 2.0× usualVacaville, 2 December: 8.1 µg/m³, 1.1× usualVacaville, 3 December: 12.4 µg/m³, 1.7× usualVacaville, 4 December: 15.4 µg/m³, 2.1× usualVacaville, 5 December: 13.4 µg/m³, 1.8× usualVacaville, 6 December: 14.3 µg/m³, 2.0× usualVacaville, 7 December: 24.8 µg/m³, 3.4× usualVacaville, 8 December: 9.6 µg/m³, 1.3× usualVacaville, 9 December: 6.7 µg/m³, 0.9× usualVacaville, 10 December: 18.8 µg/m³, 2.6× usualVacaville, 11 December: 26.8 µg/m³, 3.7× usualVacaville, 12 December: 11.7 µg/m³, 1.6× usualVacaville, 13 December: 3.8 µg/m³, 0.5× usualVacaville, 14 December: 4.1 µg/m³, 0.6× usualLivermoreLivermore, 28 November: 10.4 µg/m³, 1.5× usualLivermore, 29 November: 13.9 µg/m³, 2.0× usualLivermore, 30 November: 13.0 µg/m³, 1.9× usualLivermore, 1 December: 13.0 µg/m³, 1.9× usualLivermore, 2 December: 7.1 µg/m³, 1.0× usualLivermore, 3 December: 12.3 µg/m³, 1.8× usualLivermore, 4 December: 15.8 µg/m³, 2.3× usualLivermore, 5 December: 13.7 µg/m³, 2.0× usualLivermore, 6 December: no readingLivermore, 7 December: 22.2 µg/m³, 3.2× usualLivermore, 8 December: 13.7 µg/m³, 2.0× usualLivermore, 9 December: 4.3 µg/m³, 0.6× usualLivermore, 10 December: 19.2 µg/m³, 2.7× usualLivermore, 11 December: 25.6 µg/m³, 3.7× usualLivermore, 12 December: 10.3 µg/m³, 1.5× usualLivermore, 13 December: 4.2 µg/m³, 0.6× usualLivermore, 14 December: 6.1 µg/m³, 0.9× usual28 Nov301 Dec2468101214
The 60 cities with the highest readings of 61, in the order the episode reached them, 3 days before to 3 after. Each square is a day, coloured by that day's PM2.5; outlined: at twice the city's usual or more.
Good0–50
Moderate51–100
Sensitive groups101–150
Unhealthy151–200
Very unhealthy201–300
Hazardous301+

Every city it reached

CityDaysHighestUsualAbove usual
FontanaCalifornia, United States3 51.75 December10.05.2×
MartinezCalifornia, United States2 37.17 December7.54.9×
PortervilleCalifornia, United States9 54.86 December11.24.9×
AgouraCalifornia, United States2 29.64 December6.14.9×
VallejoCalifornia, United States3 37.67 December8.04.7×
Lake ElsinoreCalifornia, United States2 27.35 December5.94.6×
Palo AltoCalifornia, United States5 41.611 December9.24.5×
RiversideCalifornia, United States3 53.55 December12.24.4×
ConcordCalifornia, United States2 26.57 December6.14.3×
San LeandroCalifornia, United States1 27.77 December6.54.3×
ClovisCalifornia, United States10 51.36 December12.14.2×
La Crescenta-MontroseCalifornia, United States1 25.04 December5.94.2×
San RafaelCalifornia, United States1 27.97 December6.64.2×
BurbankCalifornia, United States3 44.25 December10.54.2×
Los AngelesCalifornia, United States4 45.25 December11.34.0×
Santa MonicaCalifornia, United States3 32.05 December8.04.0×
PleasantonCalifornia, United States1 27.111 December6.84.0×
Jurupa ValleyCalifornia, United States4 58.05 December14.64.0×
MercedCalifornia, United States6 51.57 December13.23.9×
San FranciscoCalifornia, United States1 32.27 December8.43.8×
VisaliaCalifornia, United States5 64.84 December17.03.8×
South San FranciscoCalifornia, United States2 30.08 December7.93.8×
WoodlandCalifornia, United States6 42.57 December11.33.8×
OaklandCalifornia, United States3 35.57 December9.63.7×
SacramentoCalifornia, United States5 35.37 December9.63.7×
VacavilleCalifornia, United States1 26.811 December7.33.7×
LivermoreCalifornia, United States1 25.611 December7.03.7×
CorcoranCalifornia, United States7 48.15 December13.23.6×
San DiegoCalifornia, United States2 37.16 December10.33.6×
MantecaCalifornia, United States9 44.07 December12.33.6×
LomitaCalifornia, United States2 28.86 December8.13.6×
MaderaCalifornia, United States8 46.47 December13.13.5×
TurlockCalifornia, United States9 46.57 December13.43.5×
HanfordCalifornia, United States9 53.85 December16.03.4×
BakersfieldCalifornia, United States9 61.07 December18.43.3×
ChicoCalifornia, United States5 29.328 November9.03.3×
OceansideCalifornia, United States2 25.96 December8.03.2×
RichmondCalifornia, United States2 32.37 December10.03.2×
GaltCalifornia, United States1 26.57 December8.33.2×
BerkeleyCalifornia, United States3 35.17 December11.03.2×
FresnoCalifornia, United States8 57.16 December18.03.2×
Chula VistaCalifornia, United States1 28.86 December9.13.2×
San JoseCalifornia, United States4 32.38 December10.33.1×
InglewoodCalifornia, United States4 32.05 December10.43.1×
Yuba CityCalifornia, United States1 26.37 December8.63.1×
AnaheimCalifornia, United States4 40.25 December13.23.0×
FlorinCalifornia, United States9 44.17 December14.53.0×
TorranceCalifornia, United States3 31.35 December10.82.9×
Arden-ArcadeCalifornia, United States4 31.47 December11.02.9×
CarsonCalifornia, United States3 34.35 December12.42.8×
StocktonCalifornia, United States3 39.04 December14.22.7×
El CajonCalifornia, United States1 26.25 December9.62.7×
Imperial BeachCalifornia, United States2 45.46 December16.72.7×
RosevilleCalifornia, United States1 26.31 December9.72.7×
MedfordOregon, United States2 30.84 December11.62.7×
ModestoCalifornia, United States4 38.84 December14.72.6×
Long BeachCalifornia, United States3 33.25 December12.62.6×
AltamontOregon, United States1 25.07 December9.52.6×
HawthorneCalifornia, United States3 32.56 December14.12.3×
ComptonCalifornia, United States1 36.75 December16.72.2×
CalexicoCalifornia, United States1 27.74 December12.72.2×

Daily means in µg/m³. Usual: the city's median for this time of year (its days within 21 days of the date, every year, leaving out the week around it). Above usual: its highest day against that.

Against other episodes in the United States

Number 16 of 131 episodes in the United States since our records began, by cities reached.

Bars: cities reached; colour: the level of the episode's highest daily reading. All 131.

Use this page

SmogRank, California, United States, December 2024: 61 cities with PM2.5 at twice their usual or more, 1 to 11 December 2024, smogrank.com/episodes/2024-12-california-united-states (accessed 3 October 2026).

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You're welcome to reuse a single chart, image or figure with this citation and a link. Terms.

An episode is a run of days when many cities close to each other (four or more within 350 km on a day, 8 or more in all) each had a daily PM2.5 mean of at least 25 µg/m³ and at least 2 times their usual for that time of year. Found in our own measurements, not picked by hand. How we find episodes. Values are each city's daily mean of its own monitors; causes are the usual kinds for a pattern like this, not a confirmed source.