SmogRank / Chile / Biobio / Chiguayante
Chiguayante, month by month
Chiguayante has a measured daily mean on 1,285 days since 1 January 2023. Its worst month was July 2024, at 133 US AQI (48.3 µg/m³), 33rd of 2,566 cities on that month's world ranking. Its cleanest was December 2025, at 63 US AQI (15.6 µg/m³). 2025 averaged 82 US AQI (25.6 µg/m³), against 85 US AQI (27.2 µg/m³) in 2024.
Every month since 2023
The US EPA's Air Quality Index for PM2.5 (2024 breakpoints). Show values as: µg/m³ · US AQI · India AQI · China AQI · European AQI · UK DAQI · Canada AQHI+. About the scales
Months without a mean, and why
3 months
| Month | Why |
|---|---|
| Oct 2023 | 21 of 31 days measured; a month needs 22. The others: 10 with under 18 hours of readings or readings that failed our checks. |
| Mar 2023 | 11 of 31 days measured; a month needs 22. The others: 20 missing from OpenAQ's archive. |
| Feb 2023 | 3 of 28 days measured; a month needs 20. The others: 25 missing from OpenAQ's archive. |
A day counts once 18 hours of it are measured; a month needs 70% of its days.
Chiguayante's worst months
| Month | US AQI | World rank | Episode |
|---|---|---|---|
| July 2024 | 13348.3 µg/m³ | 33rdof 2,566 | Southern Chile, July 2024 South-western Chile, July 2024and 1 more |
| May 2024 | 11742.2 µg/m³ | 41stof 2,684 | South-western Chile, 14 to 19 May 2024 |
| August 2024 | 10135.5 µg/m³ | 37thof 2,010 | South-western Chile, 29 August to 1 September 2024 South-western Chile, 18 to 20 August 2024and 1 more |
| May 2026 | 9935.0 µg/m³ | 127thof 3,243 | Chile, May 2026 |
| June 2025 | 9834.5 µg/m³ | 93rdof 3,112 | – |
| May 2025 | 9532.5 µg/m³ | 120thof 3,125 | – |
Monthly means over the days measured; finished months only. World rank: its place on that month's world ranking of every city with enough days. Each month opens that ranking.
Chiguayante's worst days
| Day | US AQI | Episode |
|---|---|---|
| 24 Mar 2025 | 189110.0 µg/m³ | – |
| 9 Jul 2024 | 18198.5 µg/m³ | – |
| 16 May 2024 | 16575.3 µg/m³ | South-western Chile, 14 to 19 May 2024 |
| 10 Jul 2024 | 16271.0 µg/m³ | – |
| 15 May 2024 | 16170.0 µg/m³ | South-western Chile, 14 to 19 May 2024 |
| 13 Aug 2024 | 16068.9 µg/m³ | Southern Chile, 12 to 13 August 2024 |
| 25 May 2026 | 15865.3 µg/m³ | Chile, May 2026 |
| 13 Jul 2024 | 15764.5 µg/m³ | Chile, July 2024 |
| 11 Jul 2024 | 15764.1 µg/m³ | Chile, July 2024 |
| 20 Jul 2024 | 15763.6 µg/m³ | South-western Chile, July 2024 |
Daily means, the highest since 1 Jan 2023; the WHO's daily guideline is 15 µg/m³. Each date opens that day's world ranking, and each episode the bad-air spell it was part of.
Use this history
SmogRank, PM2.5 monthly and daily means, Chiguayante, Chile, 1 Jan 2023 – 12 Oct 2026. Monitor data from Chile - SINCA via OpenAQ; sources listed at smogrank.com/sources. smogrank.com/cl/chiguayante/history (accessed 14 Oct 2026).
You're welcome to reuse a single chart, image or figure with this citation and a link. Terms. Raw monitor readings in bulk are published by OpenAQ, under each provider's licence.
Chiguayante now: the last 24 hours, its ranks today and the last 12 months day by day.
Updated 2026-10-14 03:07 UTC. Values are PM2.5 (fine particles), the median of each city's monitors, as the US AQI PM2.5 sub-index. Some low-cost readings: Sensor.Community, ODbL (data and licence). Some readings: Uzhydromet (Uzbekistan's Hydrometeorological Service); Department of Environment, Nepal; Vietnam's government monitors; Aurassure; Umhverfisstofnun (Environment Agency of Iceland); RMCAB (Secretaría Distrital de Ambiente, Bogotá); Love My Air (City and County of Denver), no reuse terms published (why we use them).