SmogRank / Episodes / Chile

South-western Chile, July 2023

For 2 days, from 17 to 18 July 2023, 13 cities in Chile had PM2.5 at least twice their usual for the time of year. The worst reading was Osorno, Los Lagos Region, Chile: 295.0 µg/m³ on 18 July, about 5.1× its usual 58.0.

No cause namedWe have no fire or smoke records for these days, so we only say what the measurements show.
Cities reached13in 1 country
Days217 to 18 July 2023
Worst day18 July12 cities counted
Furthest above usual5.1×Osorno

Day by day

18 July 12 cities at twice their usual or more
TemucoHualquiChiguayanteLotaCoronelCuranilahueConcepciónToméCauquenesValdiviaTalcaCuricóRengoTalagantePuente AltoSan Pedro de la PazLinaresNacimientoRancaguaHualpénTalcahuanoChillánLa UniónLos ÁngelesPuerto VarasSan CarlosPuerto MonttOsorno
14 Jul15161718192021
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

Puerto MonttPuerto Montt, 14 July: no readingPuerto Montt, 15 July: no readingPuerto Montt, 16 July: 82.4 µg/m³, 2.2× usualPuerto Montt, 17 July: 148.5 µg/m³, 4.0× usualPuerto Montt, 18 July: 96.3 µg/m³, 2.6× usualPuerto Montt, 19 July: 26.9 µg/m³, 0.7× usualPuerto Montt, 20 July: 21.5 µg/m³, 0.6× usualPuerto Montt, 21 July: 26.1 µg/m³, 0.7× usualNacimientoNacimiento, 14 July: no readingNacimiento, 15 July: no readingNacimiento, 16 July: 47.4 µg/m³, 0.7× usualNacimiento, 17 July: 138.0 µg/m³, 2.0× usualNacimiento, 18 July: 151.5 µg/m³, 2.2× usualNacimiento, 19 July: 115.5 µg/m³, 1.7× usualNacimiento, 20 July: 62.6 µg/m³, 0.9× usualNacimiento, 21 July: 34.1 µg/m³, 0.5× usualRancaguaRancagua, 14 July: no readingRancagua, 15 July: no readingRancagua, 16 July: 76.7 µg/m³, 1.4× usualRancagua, 17 July: 129.0 µg/m³, 2.4× usualRancagua, 18 July: 92.3 µg/m³, 1.7× usualRancagua, 19 July: 64.3 µg/m³, 1.2× usualRancagua, 20 July: 74.1 µg/m³, 1.4× usualRancagua, 21 July: 45.8 µg/m³, 0.9× usualOsornoOsorno, 14 July: no readingOsorno, 15 July: no readingOsorno, 16 July: 112.0 µg/m³, 1.9× usualOsorno, 17 July: 122.0 µg/m³, 2.1× usualOsorno, 18 July: 295.0 µg/m³, 5.1× usualOsorno, 19 July: 50.4 µg/m³, 0.9× usualOsorno, 20 July: 26.2 µg/m³, 0.5× usualOsorno, 21 July: 28.3 µg/m³, 0.5× usualSan CarlosSan Carlos, 14 July: no readingSan Carlos, 15 July: no readingSan Carlos, 16 July: 37.5 µg/m³, 0.8× usualSan Carlos, 17 July: 101.0 µg/m³, 2.3× usualSan Carlos, 18 July: 170.0 µg/m³, 3.8× usualSan Carlos, 19 July: 67.1 µg/m³, 1.5× usualSan Carlos, 20 July: 35.7 µg/m³, 0.8× usualSan Carlos, 21 July: 16.8 µg/m³, 0.4× usualHualpénHualpén, 14 July: no readingHualpén, 15 July: no readingHualpén, 16 July: 104.0 µg/m³, 1.6× usualHualpén, 17 July: 122.0 µg/m³, 1.9× usualHualpén, 18 July: 157.0 µg/m³, 2.5× usualHualpén, 19 July: 104.0 µg/m³, 1.6× usualHualpén, 20 July: 24.7 µg/m³, 0.4× usualHualpén, 21 July: 28.4 µg/m³, 0.4× usualPuerto VarasPuerto Varas, 14 July: no readingPuerto Varas, 15 July: no readingPuerto Varas, 16 July: 85.9 µg/m³, 1.6× usualPuerto Varas, 17 July: 99.7 µg/m³, 1.9× usualPuerto Varas, 18 July: 152.0 µg/m³, 2.9× usualPuerto Varas, 19 July: 22.7 µg/m³, 0.4× usualPuerto Varas, 20 July: 21.8 µg/m³, 0.4× usualPuerto Varas, 21 July: 24.0 µg/m³, 0.5× usualLa UniónLa Unión, 14 July: no readingLa Unión, 15 July: no readingLa Unión, 16 July: 53.4 µg/m³, 1.2× usualLa Unión, 17 July: 82.9 µg/m³, 1.9× usualLa Unión, 18 July: 118.0 µg/m³, 2.7× usualLa Unión, 19 July: 32.5 µg/m³, 0.7× usualLa Unión, 20 July: 21.4 µg/m³, 0.5× usualLa Unión, 21 July: 28.7 µg/m³, 0.7× usualChillánChillán, 14 July: no readingChillán, 15 July: no readingChillán, 16 July: 31.3 µg/m³, 0.8× usualChillán, 17 July: 72.7 µg/m³, 1.8× usualChillán, 18 July: 110.3 µg/m³, 2.7× usualChillán, 19 July: 75.4 µg/m³, 1.8× usualChillán, 20 July: 59.7 µg/m³, 1.5× usualChillán, 21 July: 18.8 µg/m³, 0.5× usualLos ÁngelesLos Ángeles, 14 July: no readingLos Ángeles, 15 July: no readingLos Ángeles, 16 July: 24.8 µg/m³, 0.7× usualLos Ángeles, 17 July: 51.3 µg/m³, 1.4× usualLos Ángeles, 18 July: 106.4 µg/m³, 2.9× usualLos Ángeles, 19 July: 66.5 µg/m³, 1.8× usualLos Ángeles, 20 July: 43.9 µg/m³, 1.2× usualLos Ángeles, 21 July: 17.9 µg/m³, 0.5× usualLinaresLinares, 14 July: no readingLinares, 15 July: no readingLinares, 16 July: 48.7 µg/m³, 1.0× usualLinares, 17 July: 84.0 µg/m³, 1.7× usualLinares, 18 July: 103.0 µg/m³, 2.1× usualLinares, 19 July: 93.9 µg/m³, 1.9× usualLinares, 20 July: 87.2 µg/m³, 1.8× usualLinares, 21 July: 20.6 µg/m³, 0.4× usualTalcahuanoTalcahuano, 14 July: no readingTalcahuano, 15 July: no readingTalcahuano, 16 July: 48.5 µg/m³, 1.3× usualTalcahuano, 17 July: 63.4 µg/m³, 1.6× usualTalcahuano, 18 July: 97.0 µg/m³, 2.5× usualTalcahuano, 19 July: 49.2 µg/m³, 1.3× usualTalcahuano, 20 July: 15.5 µg/m³, 0.4× usualTalcahuano, 21 July: 16.6 µg/m³, 0.4× usualSan Pedro de la PazSan Pedro de la Paz, 14 July: no readingSan Pedro de la Paz, 15 July: no readingSan Pedro de la Paz, 16 July: 26.9 µg/m³, 1.0× usualSan Pedro de la Paz, 17 July: 35.4 µg/m³, 1.3× usualSan Pedro de la Paz, 18 July: 58.7 µg/m³, 2.1× usualSan Pedro de la Paz, 19 July: 53.8 µg/m³, 1.9× usualSan Pedro de la Paz, 20 July: 12.8 µg/m³, 0.5× usualSan Pedro de la Paz, 21 July: 15.3 µg/m³, 0.6× usual14 Jul15161718192021
Every counted city, 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
OsornoLos Lagos Region, Chile2 295.018 July58.05.1×
Puerto MonttLos Lagos Region, Chile2 148.517 July37.34.0×
San CarlosÑuble, Chile2 170.018 July44.23.8×
Los ÁngelesBiobio, Chile1 106.418 July37.22.9×
Puerto VarasLos Lagos Region, Chile1 152.018 July53.32.9×
La UniónLos Ríos Region, Chile1 118.018 July43.82.7×
ChillánÑuble, Chile1 110.318 July41.02.7×
TalcahuanoBiobio, Chile1 97.018 July38.52.5×
HualpénBiobio, Chile1 157.018 July63.42.5×
RancaguaO'Higgins Region, Chile1 129.017 July53.72.4×
NacimientoBiobio, Chile2 151.518 July69.32.2×
San Pedro de la PazBiobio, Chile1 58.718 July27.82.1×
LinaresMaule Region, Chile1 103.018 July49.02.1×

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 Chile

Number 12 of 30 episodes in Chile since our records began, by cities reached.

Bars: cities reached; colour: the level of the episode's highest daily reading. All 30.

Use this page

SmogRank, South-western Chile, July 2023: 13 cities with PM2.5 at twice their usual or more, 17 to 18 July 2023, smogrank.com/episodes/2023-07-south-western-chile (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.