SmogRank / Episodes / France

France, The Netherlands and United Kingdom, January 2023

For 5 days, from 21 to 25 January 2023, 66 cities in France, The Netherlands and the United Kingdom had PM2.5 at least twice their usual for the time of year. The worst reading was Tilburg, North Brabant, The Netherlands: 52.1 µg/m³ on 25 January, about 4.0× its usual 13.1.

No cause namedWe have no fire or smoke records for these days, so we only say what the measurements show.
Cities reached66in 3 countries
Days521 to 25 January 2023
Worst day25 January43 cities counted
Furthest above usual7.2×Reading

Day by day

25 January 43 cities at twice their usual or more
DieppeBoulogne-sur-MerCalaisCanterburyCreilDomontSeafordRambouilletSarcellesChartresSouthend-on-SeaBrightonSainte-Geneviève-des-BoisCanvey IslandKoksijdeÉtampesGraysClacton-on-SeaDagenhamAlençonMelunMenenRoeselareFontainebleauDenainIzegemCoulommiersKortrijkTournaiOlivetLe MansWaregemBloisNewmarketMontargisMaldegemPortsmouthGentNorwichToursEvergemMonsJoué-lès-ToursLochristiÉpernayReimsCherbourgAndoverBourgesAuxerreBrusselsCharleroiChâteaurouxBeverenGrimbergenWillebroekTroyesZwijndrechtZaventemRixensartAntwerpMechelenStabroekKapellenPoitiersSpijkenisseNamurRoyal Leamington SpaSchiedamAarschotAndenneMontluçonSaint-DizierMoulinsMolMarche-en-FamenneKingston upon HullLimogesHasseltVelserbroekVerdunFlémalle-HauteHouthalenGenkLiègeAngoulêmeMontceau-les-MinesClermont-FerrandDijonNewportYorkEsch-sur-AlzetteHeerlenChalon-sur-SaôneBarneveldLuxembourgAachenThionvilleNewton AbbotMetzNancyVenloMâconJülichMönchengladbachJüchenTrierLunévilleBriton FerryVesoulLons-le-SaunierKrefeldBergheimBourg-en-BresseBesançonÉpinalPlymouthDillingenBarnstaplePrestonLyonSaltashWeselGivorsMeyzieuDüsseldorfForbachDuisburgRatingenKölnSaarbrückenOberhausenLeverkusenBonnBorkenEssenSolingenGelsenkirchenBrestEnschedeMontbéliardHattingenGroningenNeuwiedAnnemasseDattelnKoblenzBendorfAnnecyHagenDortmundChambéryMulhouseSchwerteLüdenscheidLingenMünsterAlbertvilleSallanchesMüllheimAostaOrléansAngersMaarssenVannesVelsen-ZuidLa RochelleLa Roche-sur-YonNantesParisIJsselsteinZaanstadLorientSaint-NazaireAmiensBadhoevedorpUtrecht's-GravenzandeMaassluisNiortBéthuneLe HavreValenciennesSaint-QuentinAmsterdamNijmegenRotterdamMedemblikRidderkerkManchesterRennesEindhovenPurmerendThe HagueBirminghamBeauvaisBredaLisieuxDouaiDreuxÉvreuxHillegomNottinghamSheffieldWarringtonWiganBexleyLondonRoubaixCardiffTilburgRouenVenrayCaenLilleIrlamLeedsSouthamptonDunkirkChesterfieldLiverpoolSpekeStoke-on-TrentOxfordSaint-BrieucHayesReading
18 Jan19202122232425262728
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

TilburgTilburg, 18 January: 16.2 µg/m³, 1.2× usualTilburg, 19 January: 14.4 µg/m³, 1.1× usualTilburg, 20 January: 16.6 µg/m³, 1.3× usualTilburg, 21 January: 27.4 µg/m³, 2.1× usualTilburg, 22 January: 13.6 µg/m³, 1.0× usualTilburg, 23 January: 18.0 µg/m³, 1.4× usualTilburg, 24 January: 18.1 µg/m³, 1.4× usualTilburg, 25 January: 52.1 µg/m³, 4.0× usualTilburg, 26 January: 17.7 µg/m³, 1.4× usualTilburg, 27 January: 8.7 µg/m³, 0.7× usualTilburg, 28 January: 12.9 µg/m³, 1.0× usualEindhovenEindhoven, 18 January: 19.0 µg/m³, 1.4× usualEindhoven, 19 January: 19.7 µg/m³, 1.5× usualEindhoven, 20 January: 19.4 µg/m³, 1.4× usualEindhoven, 21 January: 30.4 µg/m³, 2.3× usualEindhoven, 22 January: 16.6 µg/m³, 1.2× usualEindhoven, 23 January: 18.5 µg/m³, 1.4× usualEindhoven, 24 January: 20.6 µg/m³, 1.5× usualEindhoven, 25 January: 46.6 µg/m³, 3.5× usualEindhoven, 26 January: 21.0 µg/m³, 1.6× usualEindhoven, 27 January: 10.6 µg/m³, 0.8× usualEindhoven, 28 January: 17.4 µg/m³, 1.3× usualVenrayVenray, 18 January: 14.5 µg/m³, 1.3× usualVenray, 19 January: 14.4 µg/m³, 1.3× usualVenray, 20 January: 16.6 µg/m³, 1.5× usualVenray, 21 January: 27.6 µg/m³, 2.5× usualVenray, 22 January: 13.4 µg/m³, 1.2× usualVenray, 23 January: 15.3 µg/m³, 1.4× usualVenray, 24 January: 17.9 µg/m³, 1.6× usualVenray, 25 January: 45.9 µg/m³, 4.1× usualVenray, 26 January: 16.6 µg/m³, 1.5× usualVenray, 27 January: 6.7 µg/m³, 0.6× usualVenray, 28 January: 12.0 µg/m³, 1.1× usualRoubaixRoubaix, 18 January: 16.8 µg/m³, 1.5× usualRoubaix, 19 January: no readingRoubaix, 20 January: 11.8 µg/m³, 1.0× usualRoubaix, 21 January: 28.4 µg/m³, 2.5× usualRoubaix, 22 January: 22.9 µg/m³, 2.0× usualRoubaix, 23 January: 24.3 µg/m³, 2.1× usualRoubaix, 24 January: 25.5 µg/m³, 2.2× usualRoubaix, 25 January: 45.4 µg/m³, 3.9× usualRoubaix, 26 January: 16.6 µg/m³, 1.4× usualRoubaix, 27 January: 8.4 µg/m³, 0.7× usualRoubaix, 28 January: no readingLilleLille, 18 January: 15.6 µg/m³, 1.5× usualLille, 19 January: no readingLille, 20 January: 11.7 µg/m³, 1.1× usualLille, 21 January: 29.4 µg/m³, 2.8× usualLille, 22 January: no readingLille, 23 January: 26.1 µg/m³, 2.5× usualLille, 24 January: 26.9 µg/m³, 2.6× usualLille, 25 January: 45.0 µg/m³, 4.3× usualLille, 26 January: 19.4 µg/m³, 1.9× usualLille, 27 January: 9.9 µg/m³, 1.0× usualLille, 28 January: 19.4 µg/m³, 1.9× usualDouaiDouai, 18 January: 13.4 µg/m³, 1.2× usualDouai, 19 January: 14.3 µg/m³, 1.3× usualDouai, 20 January: 9.1 µg/m³, 0.8× usualDouai, 21 January: 27.6 µg/m³, 2.5× usualDouai, 22 January: 24.2 µg/m³, 2.2× usualDouai, 23 January: 27.8 µg/m³, 2.5× usualDouai, 24 January: 31.0 µg/m³, 2.8× usualDouai, 25 January: 40.9 µg/m³, 3.7× usualDouai, 26 January: 17.7 µg/m³, 1.6× usualDouai, 27 January: 9.4 µg/m³, 0.8× usualDouai, 28 January: 20.9 µg/m³, 1.9× usualValenciennesValenciennes, 18 January: 19.7 µg/m³, 1.8× usualValenciennes, 19 January: no readingValenciennes, 20 January: 11.4 µg/m³, 1.0× usualValenciennes, 21 January: 27.2 µg/m³, 2.4× usualValenciennes, 22 January: 21.7 µg/m³, 1.9× usualValenciennes, 23 January: 26.0 µg/m³, 2.3× usualValenciennes, 24 January: 26.5 µg/m³, 2.4× usualValenciennes, 25 January: 37.0 µg/m³, 3.3× usualValenciennes, 26 January: 20.4 µg/m³, 1.8× usualValenciennes, 27 January: 7.7 µg/m³, 0.7× usualValenciennes, 28 January: 20.9 µg/m³, 1.9× usual's-Gravenzande's-Gravenzande, 18 January: 3.0 µg/m³, 0.3× usual's-Gravenzande, 19 January: 3.8 µg/m³, 0.3× usual's-Gravenzande, 20 January: 8.3 µg/m³, 0.8× usual's-Gravenzande, 21 January: 25.3 µg/m³, 2.3× usual's-Gravenzande, 22 January: 8.7 µg/m³, 0.8× usual's-Gravenzande, 23 January: 13.2 µg/m³, 1.2× usual's-Gravenzande, 24 January: 19.7 µg/m³, 1.8× usual's-Gravenzande, 25 January: 34.1 µg/m³, 3.1× usual's-Gravenzande, 26 January: 12.0 µg/m³, 1.1× usual's-Gravenzande, 27 January: 5.0 µg/m³, 0.5× usual's-Gravenzande, 28 January: 6.5 µg/m³, 0.6× usualBéthuneBéthune, 18 January: 13.3 µg/m³, 1.4× usualBéthune, 19 January: no readingBéthune, 20 January: 11.3 µg/m³, 1.2× usualBéthune, 21 January: 30.7 µg/m³, 3.2× usualBéthune, 22 January: no readingBéthune, 23 January: 26.5 µg/m³, 2.8× usualBéthune, 24 January: no readingBéthune, 25 January: no readingBéthune, 26 January: no readingBéthune, 27 January: 9.8 µg/m³, 1.0× usualBéthune, 28 January: 22.3 µg/m³, 2.3× usualWiganWigan, 18 January: 7.1 µg/m³, 0.9× usualWigan, 19 January: 10.8 µg/m³, 1.4× usualWigan, 20 January: 8.6 µg/m³, 1.1× usualWigan, 21 January: 26.5 µg/m³, 3.5× usualWigan, 22 January: no readingWigan, 23 January: 22.1 µg/m³, 2.9× usualWigan, 24 January: 29.2 µg/m³, 3.9× usualWigan, 25 January: 22.6 µg/m³, 3.0× usualWigan, 26 January: 9.6 µg/m³, 1.3× usualWigan, 27 January: 7.4 µg/m³, 1.0× usualWigan, 28 January: 11.8 µg/m³, 1.6× usualRouenRouen, 18 January: 14.1 µg/m³, 1.4× usualRouen, 19 January: 20.8 µg/m³, 2.1× usualRouen, 20 January: 18.4 µg/m³, 1.8× usualRouen, 21 January: 18.8 µg/m³, 1.9× usualRouen, 22 January: 26.4 µg/m³, 2.6× usualRouen, 23 January: 21.5 µg/m³, 2.2× usualRouen, 24 January: 28.2 µg/m³, 2.8× usualRouen, 25 January: 40.7 µg/m³, 4.1× usualRouen, 26 January: 20.7 µg/m³, 2.1× usualRouen, 27 January: 8.9 µg/m³, 0.9× usualRouen, 28 January: 16.0 µg/m³, 1.6× usualSaint-BrieucSaint-Brieuc, 18 January: no readingSaint-Brieuc, 19 January: no readingSaint-Brieuc, 20 January: no readingSaint-Brieuc, 21 January: no readingSaint-Brieuc, 22 January: 36.9 µg/m³, 4.9× usualSaint-Brieuc, 23 January: no readingSaint-Brieuc, 24 January: no readingSaint-Brieuc, 25 January: no readingSaint-Brieuc, 26 January: no readingSaint-Brieuc, 27 January: no readingSaint-Brieuc, 28 January: no readingLisieuxLisieux, 18 January: 11.0 µg/m³, 1.2× usualLisieux, 19 January: 14.1 µg/m³, 1.5× usualLisieux, 20 January: 18.5 µg/m³, 2.0× usualLisieux, 21 January: 20.2 µg/m³, 2.2× usualLisieux, 22 January: 31.7 µg/m³, 3.4× usualLisieux, 23 January: 21.8 µg/m³, 2.4× usualLisieux, 24 January: 27.2 µg/m³, 3.0× usualLisieux, 25 January: 33.8 µg/m³, 3.7× usualLisieux, 26 January: 10.9 µg/m³, 1.2× usualLisieux, 27 January: 6.6 µg/m³, 0.7× usualLisieux, 28 January: 12.6 µg/m³, 1.4× usualRennesRennes, 18 January: 4.2 µg/m³, 0.5× usualRennes, 19 January: 7.9 µg/m³, 0.9× usualRennes, 20 January: 19.8 µg/m³, 2.3× usualRennes, 21 January: 15.8 µg/m³, 1.8× usualRennes, 22 January: 27.3 µg/m³, 3.2× usualRennes, 23 January: 18.7 µg/m³, 2.2× usualRennes, 24 January: 25.7 µg/m³, 3.0× usualRennes, 25 January: 30.5 µg/m³, 3.5× usualRennes, 26 January: 12.3 µg/m³, 1.4× usualRennes, 27 January: 6.4 µg/m³, 0.7× usualRennes, 28 January: 11.2 µg/m³, 1.3× usualNantesNantes, 18 January: no readingNantes, 19 January: no readingNantes, 20 January: no readingNantes, 21 January: no readingNantes, 22 January: 29.5 µg/m³, 2.8× usualNantes, 23 January: no readingNantes, 24 January: no readingNantes, 25 January: no readingNantes, 26 January: no readingNantes, 27 January: no readingNantes, 28 January: no readingLa Roche-sur-YonLa Roche-sur-Yon, 18 January: no readingLa Roche-sur-Yon, 19 January: no readingLa Roche-sur-Yon, 20 January: no readingLa Roche-sur-Yon, 21 January: no readingLa Roche-sur-Yon, 22 January: 29.4 µg/m³, 2.8× usualLa Roche-sur-Yon, 23 January: no readingLa Roche-sur-Yon, 24 January: no readingLa Roche-sur-Yon, 25 January: no readingLa Roche-sur-Yon, 26 January: no readingLa Roche-sur-Yon, 27 January: no readingLa Roche-sur-Yon, 28 January: no readingLorientLorient, 18 January: 6.4 µg/m³, 0.6× usualLorient, 19 January: 10.8 µg/m³, 1.1× usualLorient, 20 January: 20.8 µg/m³, 2.0× usualLorient, 21 January: 16.7 µg/m³, 1.6× usualLorient, 22 January: 26.4 µg/m³, 2.6× usualLorient, 23 January: 19.4 µg/m³, 1.9× usualLorient, 24 January: 19.1 µg/m³, 1.9× usualLorient, 25 January: 29.2 µg/m³, 2.9× usualLorient, 26 January: 7.1 µg/m³, 0.7× usualLorient, 27 January: 5.5 µg/m³, 0.5× usualLorient, 28 January: 7.7 µg/m³, 0.8× usualOrléansOrléans, 18 January: no readingOrléans, 19 January: no readingOrléans, 20 January: no readingOrléans, 21 January: no readingOrléans, 22 January: 26.2 µg/m³, 2.3× usualOrléans, 23 January: no readingOrléans, 24 January: no readingOrléans, 25 January: no readingOrléans, 26 January: no readingOrléans, 27 January: no readingOrléans, 28 January: no readingReadingReading, 18 January: 15.7 µg/m³, 2.5× usualReading, 19 January: 8.5 µg/m³, 1.3× usualReading, 20 January: 8.9 µg/m³, 1.4× usualReading, 21 January: 12.6 µg/m³, 2.0× usualReading, 22 January: no readingReading, 23 January: 45.6 µg/m³, 7.2× usualReading, 24 January: no readingReading, 25 January: no readingReading, 26 January: 12.7 µg/m³, 2.0× usualReading, 27 January: 4.9 µg/m³, 0.8× usualReading, 28 January: 9.1 µg/m³, 1.4× usualHayesHayes, 18 January: 12.5 µg/m³, 1.7× usualHayes, 19 January: 6.1 µg/m³, 0.8× usualHayes, 20 January: 6.8 µg/m³, 0.9× usualHayes, 21 January: 10.6 µg/m³, 1.4× usualHayes, 22 January: no readingHayes, 23 January: 44.5 µg/m³, 6.0× usualHayes, 24 January: 18.4 µg/m³, 2.5× usualHayes, 25 January: 26.2 µg/m³, 3.5× usualHayes, 26 January: 14.7 µg/m³, 2.0× usualHayes, 27 January: 5.2 µg/m³, 0.7× usualHayes, 28 January: 9.7 µg/m³, 1.3× usualLeedsLeeds, 18 January: 6.0 µg/m³, 0.7× usualLeeds, 19 January: 7.6 µg/m³, 0.9× usualLeeds, 20 January: 6.6 µg/m³, 0.8× usualLeeds, 21 January: 17.4 µg/m³, 2.0× usualLeeds, 22 January: no readingLeeds, 23 January: 38.0 µg/m³, 4.4× usualLeeds, 24 January: 31.0 µg/m³, 3.6× usualLeeds, 25 January: 11.7 µg/m³, 1.3× usualLeeds, 26 January: 6.6 µg/m³, 0.8× usualLeeds, 27 January: 6.8 µg/m³, 0.8× usualLeeds, 28 January: 8.3 µg/m³, 1.0× usualLondonLondon, 18 January: 9.7 µg/m³, 1.1× usualLondon, 19 January: 10.2 µg/m³, 1.2× usualLondon, 20 January: 7.1 µg/m³, 0.8× usualLondon, 21 January: 18.5 µg/m³, 2.1× usualLondon, 22 January: no readingLondon, 23 January: 34.3 µg/m³, 3.9× usualLondon, 24 January: 15.2 µg/m³, 1.7× usualLondon, 25 January: 25.6 µg/m³, 2.9× usualLondon, 26 January: 7.9 µg/m³, 0.9× usualLondon, 27 January: 8.2 µg/m³, 0.9× usualLondon, 28 January: 11.9 µg/m³, 1.4× usualBexleyBexley, 18 January: 14.4 µg/m³, 1.7× usualBexley, 19 January: 8.0 µg/m³, 1.0× usualBexley, 20 January: 8.0 µg/m³, 1.0× usualBexley, 21 January: 10.1 µg/m³, 1.2× usualBexley, 22 January: no readingBexley, 23 January: 32.1 µg/m³, 3.9× usualBexley, 24 January: 18.2 µg/m³, 2.2× usualBexley, 25 January: 20.6 µg/m³, 2.5× usualBexley, 26 January: 13.3 µg/m³, 1.6× usualBexley, 27 January: 6.4 µg/m³, 0.8× usualBexley, 28 January: 9.7 µg/m³, 1.2× usualSouthamptonSouthampton, 18 January: 12.1 µg/m³, 1.7× usualSouthampton, 19 January: 8.6 µg/m³, 1.2× usualSouthampton, 20 January: 9.7 µg/m³, 1.4× usualSouthampton, 21 January: 13.5 µg/m³, 1.9× usualSouthampton, 22 January: no readingSouthampton, 23 January: 30.9 µg/m³, 4.4× usualSouthampton, 24 January: 23.8 µg/m³, 3.4× usualSouthampton, 25 January: 31.1 µg/m³, 4.4× usualSouthampton, 26 January: 15.5 µg/m³, 2.2× usualSouthampton, 27 January: 6.6 µg/m³, 0.9× usualSouthampton, 28 January: 13.0 µg/m³, 1.8× usualNottinghamNottingham, 18 January: 10.1 µg/m³, 1.2× usualNottingham, 19 January: 13.2 µg/m³, 1.6× usualNottingham, 20 January: 12.1 µg/m³, 1.5× usualNottingham, 21 January: 17.5 µg/m³, 2.1× usualNottingham, 22 January: no readingNottingham, 23 January: 24.3 µg/m³, 2.9× usualNottingham, 24 January: 32.2 µg/m³, 3.9× usualNottingham, 25 January: 29.4 µg/m³, 3.5× usualNottingham, 26 January: 15.2 µg/m³, 1.8× usualNottingham, 27 January: 13.6 µg/m³, 1.6× usualNottingham, 28 January: 17.2 µg/m³, 2.1× usualChesterfieldChesterfield, 18 January: 6.1 µg/m³, 0.9× usualChesterfield, 19 January: 5.5 µg/m³, 0.8× usualChesterfield, 20 January: 5.8 µg/m³, 0.8× usualChesterfield, 21 January: 16.0 µg/m³, 2.3× usualChesterfield, 22 January: no readingChesterfield, 23 January: 24.5 µg/m³, 3.5× usualChesterfield, 24 January: 31.6 µg/m³, 4.5× usualChesterfield, 25 January: 13.2 µg/m³, 1.9× usualChesterfield, 26 January: 4.4 µg/m³, 0.6× usualChesterfield, 27 January: 5.9 µg/m³, 0.8× usualChesterfield, 28 January: 10.7 µg/m³, 1.5× usualStoke-on-TrentStoke-on-Trent, 18 January: 6.1 µg/m³, 0.9× usualStoke-on-Trent, 19 January: 6.3 µg/m³, 0.9× usualStoke-on-Trent, 20 January: 7.0 µg/m³, 1.0× usualStoke-on-Trent, 21 January: 14.0 µg/m³, 2.1× usualStoke-on-Trent, 22 January: no readingStoke-on-Trent, 23 January: 23.5 µg/m³, 3.5× usualStoke-on-Trent, 24 January: 30.5 µg/m³, 4.6× usualStoke-on-Trent, 25 January: 21.5 µg/m³, 3.2× usualStoke-on-Trent, 26 January: 10.3 µg/m³, 1.5× usualStoke-on-Trent, 27 January: 9.4 µg/m³, 1.4× usualStoke-on-Trent, 28 January: 13.4 µg/m³, 2.0× usualLe HavreLe Havre, 18 January: 5.4 µg/m³, 0.6× usualLe Havre, 19 January: 17.3 µg/m³, 1.9× usualLe Havre, 20 January: 5.3 µg/m³, 0.6× usualLe Havre, 21 January: 17.3 µg/m³, 1.9× usualLe Havre, 22 January: 23.3 µg/m³, 2.6× usualLe Havre, 23 January: 18.6 µg/m³, 2.0× usualLe Havre, 24 January: 30.0 µg/m³, 3.3× usualLe Havre, 25 January: 28.4 µg/m³, 3.1× usualLe Havre, 26 January: 6.4 µg/m³, 0.7× usualLe Havre, 27 January: 7.2 µg/m³, 0.8× usualLe Havre, 28 January: 12.7 µg/m³, 1.4× usualManchesterManchester, 18 January: 9.4 µg/m³, 1.2× usualManchester, 19 January: 10.1 µg/m³, 1.2× usualManchester, 20 January: 8.7 µg/m³, 1.1× usualManchester, 21 January: 16.2 µg/m³, 2.0× usualManchester, 22 January: no readingManchester, 23 January: 21.7 µg/m³, 2.7× usualManchester, 24 January: 28.6 µg/m³, 3.5× usualManchester, 25 January: 18.9 µg/m³, 2.3× usualManchester, 26 January: 10.9 µg/m³, 1.3× usualManchester, 27 January: 7.3 µg/m³, 0.9× usualManchester, 28 January: 12.9 µg/m³, 1.6× usualCaenCaen, 18 January: 5.0 µg/m³, 0.7× usualCaen, 19 January: 7.0 µg/m³, 1.0× usualCaen, 20 January: 5.5 µg/m³, 0.8× usualCaen, 21 January: 12.3 µg/m³, 1.8× usualCaen, 22 January: 20.0 µg/m³, 3.0× usualCaen, 23 January: 13.8 µg/m³, 2.1× usualCaen, 24 January: 28.1 µg/m³, 4.2× usualCaen, 25 January: 27.7 µg/m³, 4.1× usualCaen, 26 January: 6.3 µg/m³, 0.9× usualCaen, 27 January: 5.3 µg/m³, 0.8× usualCaen, 28 January: 7.7 µg/m³, 1.1× usualLiverpoolLiverpool, 18 January: 4.1 µg/m³, 0.7× usualLiverpool, 19 January: 4.1 µg/m³, 0.7× usualLiverpool, 20 January: 6.3 µg/m³, 1.1× usualLiverpool, 21 January: 17.6 µg/m³, 2.9× usualLiverpool, 22 January: no readingLiverpool, 23 January: 21.0 µg/m³, 3.5× usualLiverpool, 24 January: 27.3 µg/m³, 4.6× usualLiverpool, 25 January: 15.5 µg/m³, 2.6× usualLiverpool, 26 January: 7.8 µg/m³, 1.3× usualLiverpool, 27 January: 5.0 µg/m³, 0.8× usualLiverpool, 28 January: 7.7 µg/m³, 1.3× usualSheffieldSheffield, 18 January: 5.5 µg/m³, 0.8× usualSheffield, 19 January: 5.8 µg/m³, 0.8× usualSheffield, 20 January: 4.8 µg/m³, 0.7× usualSheffield, 21 January: 13.2 µg/m³, 1.9× usualSheffield, 22 January: no readingSheffield, 23 January: 24.0 µg/m³, 3.5× usualSheffield, 24 January: 27.1 µg/m³, 3.9× usualSheffield, 25 January: 14.3 µg/m³, 2.1× usualSheffield, 26 January: 6.3 µg/m³, 0.9× usualSheffield, 27 January: 5.0 µg/m³, 0.7× usualSheffield, 28 January: 9.0 µg/m³, 1.3× usualBirminghamBirmingham, 18 January: 6.5 µg/m³, 0.9× usualBirmingham, 19 January: 6.4 µg/m³, 0.9× usualBirmingham, 20 January: 7.1 µg/m³, 0.9× usualBirmingham, 21 January: 15.7 µg/m³, 2.1× usualBirmingham, 22 January: no readingBirmingham, 23 January: 21.8 µg/m³, 2.9× usualBirmingham, 24 January: 27.1 µg/m³, 3.6× usualBirmingham, 25 January: 16.7 µg/m³, 2.2× usualBirmingham, 26 January: 9.6 µg/m³, 1.3× usualBirmingham, 27 January: 7.0 µg/m³, 0.9× usualBirmingham, 28 January: 12.4 µg/m³, 1.7× usualVannesVannes, 18 January: 4.7 µg/m³, 0.5× usualVannes, 19 January: 8.1 µg/m³, 0.8× usualVannes, 20 January: no readingVannes, 21 January: 15.0 µg/m³, 1.5× usualVannes, 22 January: 24.4 µg/m³, 2.5× usualVannes, 23 January: 18.5 µg/m³, 1.9× usualVannes, 24 January: 25.6 µg/m³, 2.6× usualVannes, 25 January: 27.1 µg/m³, 2.7× usualVannes, 26 January: 9.5 µg/m³, 1.0× usualVannes, 27 January: 5.4 µg/m³, 0.5× usualVannes, 28 January: 7.8 µg/m³, 0.8× usualSpekeSpeke, 18 January: 3.5 µg/m³, 0.6× usualSpeke, 19 January: 3.8 µg/m³, 0.7× usualSpeke, 20 January: 5.0 µg/m³, 0.9× usualSpeke, 21 January: 18.8 µg/m³, 3.2× usualSpeke, 22 January: no readingSpeke, 23 January: 21.6 µg/m³, 3.7× usualSpeke, 24 January: 26.5 µg/m³, 4.6× usualSpeke, 25 January: 13.4 µg/m³, 2.3× usualSpeke, 26 January: 4.6 µg/m³, 0.8× usualSpeke, 27 January: 3.8 µg/m³, 0.7× usualSpeke, 28 January: 7.7 µg/m³, 1.3× usualWarringtonWarrington, 18 January: 7.6 µg/m³, 1.1× usualWarrington, 19 January: 7.0 µg/m³, 1.0× usualWarrington, 20 January: 6.9 µg/m³, 1.0× usualWarrington, 21 January: 23.8 µg/m³, 3.5× usualWarrington, 22 January: no readingWarrington, 23 January: 21.7 µg/m³, 3.2× usualWarrington, 24 January: 26.2 µg/m³, 3.9× usualWarrington, 25 January: no readingWarrington, 26 January: no readingWarrington, 27 January: no readingWarrington, 28 January: no readingDunkirkDunkirk, 18 January: no readingDunkirk, 19 January: no readingDunkirk, 20 January: 8.2 µg/m³, 0.7× usualDunkirk, 21 January: no readingDunkirk, 22 January: 19.3 µg/m³, 1.7× usualDunkirk, 23 January: no readingDunkirk, 24 January: no readingDunkirk, 25 January: 50.2 µg/m³, 4.5× usualDunkirk, 26 January: 10.1 µg/m³, 0.9× usualDunkirk, 27 January: 8.8 µg/m³, 0.8× usualDunkirk, 28 January: 19.6 µg/m³, 1.8× usualBredaBreda, 18 January: 12.7 µg/m³, 1.1× usualBreda, 19 January: 10.9 µg/m³, 1.0× usualBreda, 20 January: 16.6 µg/m³, 1.5× usualBreda, 21 January: 22.7 µg/m³, 2.0× usualBreda, 22 January: 10.8 µg/m³, 1.0× usualBreda, 23 January: 13.4 µg/m³, 1.2× usualBreda, 24 January: 15.6 µg/m³, 1.4× usualBreda, 25 January: 41.6 µg/m³, 3.7× usualBreda, 26 January: 14.2 µg/m³, 1.3× usualBreda, 27 January: 4.4 µg/m³, 0.4× usualBreda, 28 January: 9.4 µg/m³, 0.8× usualNijmegenNijmegen, 18 January: 14.0 µg/m³, 1.3× usualNijmegen, 19 January: 13.6 µg/m³, 1.2× usualNijmegen, 20 January: 16.7 µg/m³, 1.5× usualNijmegen, 21 January: 24.0 µg/m³, 2.2× usualNijmegen, 22 January: 12.6 µg/m³, 1.1× usualNijmegen, 23 January: 14.4 µg/m³, 1.3× usualNijmegen, 24 January: 14.1 µg/m³, 1.3× usualNijmegen, 25 January: 37.6 µg/m³, 3.4× usualNijmegen, 26 January: 16.1 µg/m³, 1.5× usualNijmegen, 27 January: 5.4 µg/m³, 0.5× usualNijmegen, 28 January: 11.3 µg/m³, 1.0× usualPurmerendPurmerend, 18 January: 7.1 µg/m³, 0.7× usualPurmerend, 19 January: 5.1 µg/m³, 0.5× usualPurmerend, 20 January: 14.7 µg/m³, 1.4× usualPurmerend, 21 January: 20.0 µg/m³, 1.9× usualPurmerend, 22 January: 7.4 µg/m³, 0.7× usualPurmerend, 23 January: 8.6 µg/m³, 0.8× usualPurmerend, 24 January: 13.8 µg/m³, 1.3× usualPurmerend, 25 January: 36.7 µg/m³, 3.6× usualPurmerend, 26 January: 11.1 µg/m³, 1.1× usualPurmerend, 27 January: 3.6 µg/m³, 0.3× usualPurmerend, 28 January: 6.2 µg/m³, 0.6× usualBadhoevedorpBadhoevedorp, 18 January: 7.1 µg/m³, 0.6× usualBadhoevedorp, 19 January: 5.0 µg/m³, 0.4× usualBadhoevedorp, 20 January: 17.3 µg/m³, 1.4× usualBadhoevedorp, 21 January: 20.9 µg/m³, 1.7× usualBadhoevedorp, 22 January: 9.2 µg/m³, 0.8× usualBadhoevedorp, 23 January: 12.1 µg/m³, 1.0× usualBadhoevedorp, 24 January: 15.5 µg/m³, 1.3× usualBadhoevedorp, 25 January: 36.1 µg/m³, 3.0× usualBadhoevedorp, 26 January: 11.8 µg/m³, 1.0× usualBadhoevedorp, 27 January: 5.0 µg/m³, 0.4× usualBadhoevedorp, 28 January: 8.2 µg/m³, 0.7× usualCardiffCardiff, 18 January: 11.0 µg/m³, 1.2× usualCardiff, 19 January: no readingCardiff, 20 January: no readingCardiff, 21 January: no readingCardiff, 22 January: no readingCardiff, 23 January: no readingCardiff, 24 January: no readingCardiff, 25 January: 36.0 µg/m³, 4.0× usualCardiff, 26 January: 12.8 µg/m³, 1.4× usualCardiff, 27 January: 7.6 µg/m³, 0.8× usualCardiff, 28 January: 11.4 µg/m³, 1.3× usualRidderkerkRidderkerk, 18 January: 5.3 µg/m³, 0.5× usualRidderkerk, 19 January: 3.6 µg/m³, 0.3× usualRidderkerk, 20 January: 17.1 µg/m³, 1.7× usualRidderkerk, 21 January: 22.4 µg/m³, 2.2× usualRidderkerk, 22 January: 10.7 µg/m³, 1.0× usualRidderkerk, 23 January: 14.1 µg/m³, 1.4× usualRidderkerk, 24 January: 17.7 µg/m³, 1.7× usualRidderkerk, 25 January: 35.9 µg/m³, 3.5× usualRidderkerk, 26 January: 13.2 µg/m³, 1.3× usualRidderkerk, 27 January: 4.3 µg/m³, 0.4× usualRidderkerk, 28 January: 8.5 µg/m³, 0.8× usualRotterdamRotterdam, 18 January: 5.4 µg/m³, 0.5× usualRotterdam, 19 January: 3.8 µg/m³, 0.4× usualRotterdam, 20 January: 14.0 µg/m³, 1.4× usualRotterdam, 21 January: 23.8 µg/m³, 2.3× usualRotterdam, 22 January: 10.3 µg/m³, 1.0× usualRotterdam, 23 January: 14.3 µg/m³, 1.4× usualRotterdam, 24 January: 18.7 µg/m³, 1.8× usualRotterdam, 25 January: 35.4 µg/m³, 3.4× usualRotterdam, 26 January: 12.9 µg/m³, 1.3× usualRotterdam, 27 January: 4.8 µg/m³, 0.5× usualRotterdam, 28 January: 9.2 µg/m³, 0.9× usualHillegomHillegom, 18 January: 6.8 µg/m³, 0.7× usualHillegom, 19 January: 6.0 µg/m³, 0.7× usualHillegom, 20 January: 14.4 µg/m³, 1.6× usualHillegom, 21 January: 22.3 µg/m³, 2.4× usualHillegom, 22 January: 7.7 µg/m³, 0.8× usualHillegom, 23 January: 11.2 µg/m³, 1.2× usualHillegom, 24 January: 16.5 µg/m³, 1.8× usualHillegom, 25 January: 35.1 µg/m³, 3.8× usualHillegom, 26 January: 9.5 µg/m³, 1.0× usualHillegom, 27 January: 3.7 µg/m³, 0.4× usualHillegom, 28 January: 4.1 µg/m³, 0.4× usualZaanstadZaanstad, 18 January: 5.7 µg/m³, 0.5× usualZaanstad, 19 January: 5.1 µg/m³, 0.4× usualZaanstad, 20 January: 15.6 µg/m³, 1.3× usualZaanstad, 21 January: 21.0 µg/m³, 1.8× usualZaanstad, 22 January: no readingZaanstad, 23 January: 11.7 µg/m³, 1.0× usualZaanstad, 24 January: 17.0 µg/m³, 1.4× usualZaanstad, 25 January: 35.1 µg/m³, 2.9× usualZaanstad, 26 January: 12.0 µg/m³, 1.0× usualZaanstad, 27 January: 4.2 µg/m³, 0.4× usualZaanstad, 28 January: 7.2 µg/m³, 0.6× usualAmsterdamAmsterdam, 18 January: 4.9 µg/m³, 0.5× usualAmsterdam, 19 January: 4.5 µg/m³, 0.4× usualAmsterdam, 20 January: 17.6 µg/m³, 1.7× usualAmsterdam, 21 January: 20.6 µg/m³, 2.0× usualAmsterdam, 22 January: 8.4 µg/m³, 0.8× usualAmsterdam, 23 January: 10.7 µg/m³, 1.0× usualAmsterdam, 24 January: 14.4 µg/m³, 1.4× usualAmsterdam, 25 January: 34.4 µg/m³, 3.4× usualAmsterdam, 26 January: 11.1 µg/m³, 1.1× usualAmsterdam, 27 January: 3.7 µg/m³, 0.4× usualAmsterdam, 28 January: 6.4 µg/m³, 0.6× usualThe HagueThe Hague, 18 January: 4.1 µg/m³, 0.4× usualThe Hague, 19 January: 4.5 µg/m³, 0.5× usualThe Hague, 20 January: 13.0 µg/m³, 1.4× usualThe Hague, 21 January: 23.1 µg/m³, 2.5× usualThe Hague, 22 January: 7.1 µg/m³, 0.8× usualThe Hague, 23 January: 12.5 µg/m³, 1.3× usualThe Hague, 24 January: 17.0 µg/m³, 1.8× usualThe Hague, 25 January: 33.5 µg/m³, 3.6× usualThe Hague, 26 January: 11.4 µg/m³, 1.2× usualThe Hague, 27 January: 4.8 µg/m³, 0.5× usualThe Hague, 28 January: 6.8 µg/m³, 0.7× usualVelsen-ZuidVelsen-Zuid, 18 January: 5.4 µg/m³, 0.5× usualVelsen-Zuid, 19 January: 6.4 µg/m³, 0.5× usualVelsen-Zuid, 20 January: 14.1 µg/m³, 1.2× usualVelsen-Zuid, 21 January: 20.5 µg/m³, 1.7× usualVelsen-Zuid, 22 January: 6.8 µg/m³, 0.6× usualVelsen-Zuid, 23 January: 9.6 µg/m³, 0.8× usualVelsen-Zuid, 24 January: 17.3 µg/m³, 1.4× usualVelsen-Zuid, 25 January: 33.5 µg/m³, 2.8× usualVelsen-Zuid, 26 January: 10.1 µg/m³, 0.8× usualVelsen-Zuid, 27 January: 4.0 µg/m³, 0.3× usualVelsen-Zuid, 28 January: 6.1 µg/m³, 0.5× usualMaarssenMaarssen, 18 January: 8.0 µg/m³, 0.6× usualMaarssen, 19 January: 2.8 µg/m³, 0.2× usualMaarssen, 20 January: 15.2 µg/m³, 1.1× usualMaarssen, 21 January: 19.9 µg/m³, 1.5× usualMaarssen, 22 January: 9.4 µg/m³, 0.7× usualMaarssen, 23 January: 11.9 µg/m³, 0.9× usualMaarssen, 24 January: 15.6 µg/m³, 1.2× usualMaarssen, 25 January: 33.4 µg/m³, 2.5× usualMaarssen, 26 January: 15.6 µg/m³, 1.2× usualMaarssen, 27 January: 5.2 µg/m³, 0.4× usualMaarssen, 28 January: 10.5 µg/m³, 0.8× usualSaint-QuentinSaint-Quentin, 18 January: 16.9 µg/m³, 1.8× usualSaint-Quentin, 19 January: no readingSaint-Quentin, 20 January: 9.7 µg/m³, 1.0× usualSaint-Quentin, 21 January: 23.7 µg/m³, 2.5× usualSaint-Quentin, 22 January: 21.0 µg/m³, 2.2× usualSaint-Quentin, 23 January: 22.0 µg/m³, 2.3× usualSaint-Quentin, 24 January: 22.8 µg/m³, 2.4× usualSaint-Quentin, 25 January: 33.1 µg/m³, 3.4× usualSaint-Quentin, 26 January: 19.5 µg/m³, 2.0× usualSaint-Quentin, 27 January: 8.5 µg/m³, 0.9× usualSaint-Quentin, 28 January: 19.0 µg/m³, 2.0× usualMaassluisMaassluis, 18 January: 3.5 µg/m³, 0.3× usualMaassluis, 19 January: 3.4 µg/m³, 0.3× usualMaassluis, 20 January: 10.4 µg/m³, 1.0× usualMaassluis, 21 January: 23.3 µg/m³, 2.3× usualMaassluis, 22 January: 9.4 µg/m³, 0.9× usualMaassluis, 23 January: 13.5 µg/m³, 1.3× usualMaassluis, 24 January: 19.3 µg/m³, 1.9× usualMaassluis, 25 January: 32.8 µg/m³, 3.2× usualMaassluis, 26 January: 11.9 µg/m³, 1.2× usualMaassluis, 27 January: 4.1 µg/m³, 0.4× usualMaassluis, 28 January: 7.7 µg/m³, 0.8× usualIJsselsteinIJsselstein, 18 January: 6.6 µg/m³, 0.6× usualIJsselstein, 19 January: 4.7 µg/m³, 0.4× usualIJsselstein, 20 January: 14.2 µg/m³, 1.3× usualIJsselstein, 21 January: 21.1 µg/m³, 1.9× usualIJsselstein, 22 January: 10.2 µg/m³, 0.9× usualIJsselstein, 23 January: 11.1 µg/m³, 1.0× usualIJsselstein, 24 January: 15.9 µg/m³, 1.4× usualIJsselstein, 25 January: 32.0 µg/m³, 2.9× usualIJsselstein, 26 January: 18.3 µg/m³, 1.6× usualIJsselstein, 27 January: 3.8 µg/m³, 0.3× usualIJsselstein, 28 January: 6.9 µg/m³, 0.6× usualUtrechtUtrecht, 18 January: 7.7 µg/m³, 0.7× usualUtrecht, 19 January: 4.7 µg/m³, 0.5× usualUtrecht, 20 January: 18.0 µg/m³, 1.7× usualUtrecht, 21 January: 21.6 µg/m³, 2.1× usualUtrecht, 22 January: 11.5 µg/m³, 1.1× usualUtrecht, 23 January: 13.2 µg/m³, 1.3× usualUtrecht, 24 January: 16.0 µg/m³, 1.6× usualUtrecht, 25 January: 31.8 µg/m³, 3.1× usualUtrecht, 26 January: 16.2 µg/m³, 1.6× usualUtrecht, 27 January: 4.6 µg/m³, 0.4× usualUtrecht, 28 January: 7.5 µg/m³, 0.7× usualMedemblikMedemblik, 18 January: 6.8 µg/m³, 0.8× usualMedemblik, 19 January: 5.5 µg/m³, 0.6× usualMedemblik, 20 January: 14.3 µg/m³, 1.6× usualMedemblik, 21 January: 16.3 µg/m³, 1.8× usualMedemblik, 22 January: 5.5 µg/m³, 0.6× usualMedemblik, 23 January: 7.5 µg/m³, 0.8× usualMedemblik, 24 January: 12.3 µg/m³, 1.4× usualMedemblik, 25 January: 30.9 µg/m³, 3.5× usualMedemblik, 26 January: 8.1 µg/m³, 0.9× usualMedemblik, 27 January: 3.1 µg/m³, 0.3× usualMedemblik, 28 January: 3.8 µg/m³, 0.4× usualÉvreuxÉvreux, 18 January: 9.1 µg/m³, 1.1× usualÉvreux, 19 January: 9.9 µg/m³, 1.2× usualÉvreux, 20 January: 11.1 µg/m³, 1.4× usualÉvreux, 21 January: 14.5 µg/m³, 1.8× usualÉvreux, 22 January: 17.6 µg/m³, 2.2× usualÉvreux, 23 January: 16.8 µg/m³, 2.1× usualÉvreux, 24 January: 22.9 µg/m³, 2.8× usualÉvreux, 25 January: 30.7 µg/m³, 3.8× usualÉvreux, 26 January: 16.4 µg/m³, 2.0× usualÉvreux, 27 January: 7.1 µg/m³, 0.9× usualÉvreux, 28 January: 13.0 µg/m³, 1.6× usualBeauvaisBeauvais, 18 January: 14.2 µg/m³, 1.8× usualBeauvais, 19 January: no readingBeauvais, 20 January: 9.9 µg/m³, 1.2× usualBeauvais, 21 January: 17.7 µg/m³, 2.2× usualBeauvais, 22 January: 18.1 µg/m³, 2.3× usualBeauvais, 23 January: 19.3 µg/m³, 2.4× usualBeauvais, 24 January: 23.0 µg/m³, 2.9× usualBeauvais, 25 January: 29.5 µg/m³, 3.7× usualBeauvais, 26 January: 17.2 µg/m³, 2.2× usualBeauvais, 27 January: 6.6 µg/m³, 0.8× usualBeauvais, 28 January: 16.1 µg/m³, 2.0× usualParisParis, 18 January: 10.5 µg/m³, 1.1× usualParis, 19 January: 12.4 µg/m³, 1.3× usualParis, 20 January: 11.4 µg/m³, 1.2× usualParis, 21 January: 18.9 µg/m³, 1.9× usualParis, 22 January: 19.4 µg/m³, 2.0× usualParis, 23 January: 19.6 µg/m³, 2.0× usualParis, 24 January: 21.5 µg/m³, 2.2× usualParis, 25 January: 28.3 µg/m³, 2.9× usualParis, 26 January: 26.5 µg/m³, 2.7× usualParis, 27 January: 8.4 µg/m³, 0.8× usualParis, 28 January: 15.3 µg/m³, 1.5× usualAmiensAmiens, 18 January: 10.6 µg/m³, 1.2× usualAmiens, 19 January: no readingAmiens, 20 January: 6.1 µg/m³, 0.7× usualAmiens, 21 January: 18.4 µg/m³, 2.0× usualAmiens, 22 January: 18.2 µg/m³, 2.0× usualAmiens, 23 January: 18.5 µg/m³, 2.0× usualAmiens, 24 January: 21.5 µg/m³, 2.4× usualAmiens, 25 January: 27.6 µg/m³, 3.0× usualAmiens, 26 January: 14.6 µg/m³, 1.6× usualAmiens, 27 January: 6.3 µg/m³, 0.7× usualAmiens, 28 January: 13.5 µg/m³, 1.5× usualDreuxDreux, 18 January: 8.5 µg/m³, 1.2× usualDreux, 19 January: 8.9 µg/m³, 1.3× usualDreux, 20 January: 8.4 µg/m³, 1.2× usualDreux, 21 January: 15.0 µg/m³, 2.1× usualDreux, 22 January: 18.1 µg/m³, 2.5× usualDreux, 23 January: 16.1 µg/m³, 2.3× usualDreux, 24 January: 20.4 µg/m³, 2.9× usualDreux, 25 January: 27.0 µg/m³, 3.8× usualDreux, 26 January: 18.2 µg/m³, 2.6× usualDreux, 27 January: 6.3 µg/m³, 0.9× usualDreux, 28 January: 14.3 µg/m³, 2.0× usual18 Jan2022242628
The 60 cities with the highest readings of 66, 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
ReadingEngland, United Kingdom1 45.623 January6.37.2×
HayesEngland, United Kingdom2 44.523 January7.46.0×
Saint-BrieucBrittany, France1 36.922 January7.54.9×
OxfordEngland, United Kingdom1 25.523 January5.44.7×
SpekeEngland, United Kingdom1 26.524 January5.84.6×
Stoke-on-TrentEngland, United Kingdom1 30.524 January6.74.6×
LiverpoolEngland, United Kingdom1 27.324 January6.04.6×
DunkirkHauts-de-France, France1 50.225 January11.14.5×
ChesterfieldEngland, United Kingdom1 31.624 January7.04.5×
IrlamEngland, United Kingdom1 25.024 January5.74.4×
SouthamptonEngland, United Kingdom2 31.125 January7.14.4×
LeedsEngland, United Kingdom2 38.023 January8.74.4×
LilleHauts-de-France, France4 45.025 January10.44.3×
CaenNormandy, France2 28.124 January6.74.2×
VenrayLimburg, The Netherlands2 45.925 January11.14.1×
RouenNormandy, France3 40.725 January10.04.1×
CardiffWales, United Kingdom1 36.025 January9.04.0×
TilburgNorth Brabant, The Netherlands2 52.125 January13.14.0×
RoubaixHauts-de-France, France3 45.425 January11.53.9×
SheffieldEngland, United Kingdom1 27.124 January6.93.9×
LondonEngland, United Kingdom2 34.323 January8.83.9×
WiganEngland, United Kingdom1 29.224 January7.53.9×
NottinghamEngland, United Kingdom2 32.224 January8.33.9×
BexleyEngland, United Kingdom1 32.123 January8.33.9×
WarringtonEngland, United Kingdom1 26.224 January6.83.9×
HillegomSouth Holland, The Netherlands1 35.125 January9.23.8×
DreuxCentre-Val de Loire, France1 27.025 January7.13.8×
ÉvreuxNormandy, France1 30.725 January8.13.8×
BeauvaisHauts-de-France, France1 29.525 January8.03.7×
BredaNorth Brabant, The Netherlands1 41.625 January11.33.7×
LisieuxNormandy, France3 33.825 January9.23.7×
DouaiHauts-de-France, France4 40.925 January11.23.7×
BirminghamEngland, United Kingdom1 27.124 January7.53.6×
The HagueSouth Holland, The Netherlands1 33.525 January9.43.6×
PurmerendNorth Holland, The Netherlands1 36.725 January10.33.6×
RennesBrittany, France3 30.525 January8.63.5×
ManchesterEngland, United Kingdom1 28.624 January8.13.5×
RidderkerkSouth Holland, The Netherlands1 35.925 January10.33.5×
EindhovenNorth Brabant, The Netherlands2 46.625 January13.43.5×
MedemblikNorth Holland, The Netherlands1 30.925 January8.93.5×
Saint-QuentinHauts-de-France, France1 33.125 January9.63.4×
RotterdamSouth Holland, The Netherlands1 35.425 January10.33.4×
NijmegenGelderland, The Netherlands1 37.625 January11.03.4×
AmsterdamNorth Holland, The Netherlands1 34.425 January10.23.4×
ValenciennesHauts-de-France, France4 37.025 January11.23.3×
Le HavreNormandy, France2 30.024 January9.13.3×
MaassluisSouth Holland, The Netherlands1 32.825 January10.13.2×
BéthuneHauts-de-France, France2 30.721 January9.53.2×
NiortNew Aquitaine, France1 25.422 January7.93.2×
's-GravenzandeSouth Holland, The Netherlands2 34.125 January11.03.1×
UtrechtUtrecht, The Netherlands1 31.825 January10.33.1×
AmiensHauts-de-France, France1 27.625 January9.13.0×
BadhoevedorpNorth Holland, The Netherlands1 36.125 January12.23.0×
ZaanstadNorth Holland, The Netherlands1 35.125 January12.02.9×
Saint-NazairePays de la Loire, France1 26.122 January9.12.9×
LorientBrittany, France2 29.225 January10.22.9×
ParisÎle-de-France, France1 28.325 January9.92.9×
IJsselsteinUtrecht, The Netherlands1 32.025 January11.22.9×
NantesPays de la Loire, France1 29.522 January10.42.8×
La RochelleNew Aquitaine, France1 26.022 January9.22.8×
La Roche-sur-YonPays de la Loire, France1 29.422 January10.52.8×
Velsen-ZuidNorth Holland, The Netherlands1 33.525 January12.02.8×
VannesBrittany, France2 27.125 January9.92.7×
MaarssenUtrecht, The Netherlands1 33.425 January13.52.5×
AngersPays de la Loire, France1 25.022 January10.32.4×
OrléansCentre-Val de Loire, France1 26.222 January11.42.3×

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 France and The Netherlands

Number 5 of 12 episodes in France and The Netherlands since our records began, by cities reached.

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

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SmogRank, France, The Netherlands and United Kingdom, January 2023: 66 cities with PM2.5 at twice their usual or more, 21 to 25 January 2023, smogrank.com/episodes/2023-01-france-the-netherlands-and-united-kingdom (accessed 2 October 2026).

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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.