SmogRank / Episodes / Chile

Central Chile, April 2023

For 2 days, from 26 to 27 April 2023, 9 cities in Chile had PM2.5 at least twice their usual for the time of year. The worst reading was San Carlos, Ñuble, Chile: 127.0 µg/m³ on 26 April, about 3.8× its usual 33.1.

No cause namedWe have no fire or smoke records for these days, so we only say what the measurements show.
Cities reached9in 1 country
Days226 to 27 April 2023
Worst day26 April8 cities counted
Furthest above usual3.8×San Carlos

Day by day

26 April 8 cities at twice their usual or more
ToméConcepciónHualpénHualquiSan Pedro de la PazChiguayanteCoronelLotaRengoNacimientoCuranilahueTalagantePuente AltoSantiagoRancaguaCauquenesTalcahuanoLos ÁngelesCuricóTalcaLinaresChillánSan Carlos
23 Apr24252627282930
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

San CarlosSan Carlos, 23 April: 46.6 µg/m³, 1.4× usualSan Carlos, 24 April: no readingSan Carlos, 25 April: no readingSan Carlos, 26 April: 127.0 µg/m³, 3.8× usualSan Carlos, 27 April: 118.0 µg/m³, 3.6× usualSan Carlos, 28 April: 37.3 µg/m³, 1.1× usualSan Carlos, 29 April: 16.3 µg/m³, 0.5× usualSan Carlos, 30 April: 15.0 µg/m³, 0.5× usualChillánChillán, 23 April: 50.2 µg/m³, 1.5× usualChillán, 24 April: no readingChillán, 25 April: no readingChillán, 26 April: 108.0 µg/m³, 3.2× usualChillán, 27 April: 109.5 µg/m³, 3.3× usualChillán, 28 April: 38.3 µg/m³, 1.1× usualChillán, 29 April: 15.9 µg/m³, 0.5× usualChillán, 30 April: 16.5 µg/m³, 0.5× usualLinaresLinares, 23 April: 49.4 µg/m³, 1.3× usualLinares, 24 April: no readingLinares, 25 April: no readingLinares, 26 April: 89.5 µg/m³, 2.4× usualLinares, 27 April: 118.0 µg/m³, 3.1× usualLinares, 28 April: 41.7 µg/m³, 1.1× usualLinares, 29 April: 16.7 µg/m³, 0.4× usualLinares, 30 April: 16.8 µg/m³, 0.4× usualTalcaTalca, 23 April: 27.0 µg/m³, 0.9× usualTalca, 24 April: no readingTalca, 25 April: no readingTalca, 26 April: 79.6 µg/m³, 2.7× usualTalca, 27 April: 85.7 µg/m³, 2.9× usualTalca, 28 April: 29.2 µg/m³, 1.0× usualTalca, 29 April: 12.8 µg/m³, 0.4× usualTalca, 30 April: 12.8 µg/m³, 0.4× usualCuricóCuricó, 23 April: 42.6 µg/m³, 1.3× usualCuricó, 24 April: no readingCuricó, 25 April: no readingCuricó, 26 April: 79.3 µg/m³, 2.4× usualCuricó, 27 April: 79.1 µg/m³, 2.4× usualCuricó, 28 April: 37.6 µg/m³, 1.1× usualCuricó, 29 April: 17.5 µg/m³, 0.5× usualCuricó, 30 April: 13.9 µg/m³, 0.4× usualLos ÁngelesLos Ángeles, 23 April: 17.8 µg/m³, 0.6× usualLos Ángeles, 24 April: no readingLos Ángeles, 25 April: no readingLos Ángeles, 26 April: 65.7 µg/m³, 2.3× usualLos Ángeles, 27 April: 47.3 µg/m³, 1.7× usualLos Ángeles, 28 April: 21.4 µg/m³, 0.8× usualLos Ángeles, 29 April: 13.0 µg/m³, 0.5× usualLos Ángeles, 30 April: 15.3 µg/m³, 0.5× usualTalcahuanoTalcahuano, 23 April: 23.6 µg/m³, 0.8× usualTalcahuano, 24 April: no readingTalcahuano, 25 April: no readingTalcahuano, 26 April: 62.7 µg/m³, 2.2× usualTalcahuano, 27 April: 30.6 µg/m³, 1.1× usualTalcahuano, 28 April: 17.5 µg/m³, 0.6× usualTalcahuano, 29 April: 18.0 µg/m³, 0.6× usualTalcahuano, 30 April: 22.9 µg/m³, 0.8× usualCauquenesCauquenes, 23 April: 27.6 µg/m³, 1.1× usualCauquenes, 24 April: no readingCauquenes, 25 April: no readingCauquenes, 26 April: 54.0 µg/m³, 2.2× usualCauquenes, 27 April: 55.1 µg/m³, 2.2× usualCauquenes, 28 April: 19.3 µg/m³, 0.8× usualCauquenes, 29 April: 12.1 µg/m³, 0.5× usualCauquenes, 30 April: 13.5 µg/m³, 0.5× usualRancaguaRancagua, 23 April: 31.8 µg/m³, 1.0× usualRancagua, 24 April: no readingRancagua, 25 April: no readingRancagua, 26 April: 53.7 µg/m³, 1.7× usualRancagua, 27 April: 68.0 µg/m³, 2.2× usualRancagua, 28 April: 61.1 µg/m³, 2.0× usualRancagua, 29 April: 25.4 µg/m³, 0.8× usualRancagua, 30 April: 13.9 µg/m³, 0.5× usual23 Apr24252627282930
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
San CarlosÑuble, Chile2 127.026 April33.13.8×
ChillánÑuble, Chile2 109.527 April33.43.3×
LinaresMaule Region, Chile2 118.027 April37.53.1×
TalcaMaule Region, Chile2 85.727 April29.42.9×
CuricóMaule Region, Chile2 79.326 April33.02.4×
Los ÁngelesBiobio, Chile1 65.726 April28.32.3×
TalcahuanoBiobio, Chile1 62.726 April27.92.2×
RancaguaO'Higgins Region, Chile1 68.027 April30.72.2×
CauquenesMaule Region, Chile2 55.127 April25.12.2×

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 Chile

Number 26 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, Central Chile, April 2023: 9 cities with PM2.5 at twice their usual or more, 26 to 27 April 2023, smogrank.com/episodes/2023-04-central-chile (accessed 3 October 2026).

Download top 10 (PNG)

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.