SmogRank / Chile / Biobio / Laja
Laja, month by month
Laja has a measured daily mean on 920 days since 1 January 2023. Its worst month was June 2025, at 163 US AQI (73.2 µg/m³), 6th of 2,508 cities on that month's world ranking. Its cleanest was December 2023, at 65 US AQI (16.4 µg/m³).
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
18 months
| Month | Why |
|---|---|
| Oct 2026 | No day measured. The others: 11 with no readings from the monitor. |
| Feb 2026 | 18 of 28 days measured; a month needs 20. The others: 4 with readings for part of the day (a day needs 18 hours), 6 with readings left out by our checks. |
| Jan 2026 | 21 of 31 days measured; a month needs 22. The others: 1 with no readings from the monitor, 7 with readings for part of the day (a day needs 18 hours), 2 with readings left out by our checks. |
| Dec 2025 | 13 of 31 days measured; a month needs 22. The others: 6 with readings for part of the day (a day needs 18 hours), 12 with readings left out by our checks. |
| Nov 2025 | 9 of 30 days measured; a month needs 21. The others: 10 with no readings from the monitor, 6 with readings for part of the day (a day needs 18 hours), 5 with readings left out by our checks. |
| Oct 2025 | 18 of 31 days measured; a month needs 22. The others: 8 with no readings from the monitor, 5 with readings for part of the day (a day needs 18 hours). |
| Mar 2025 | 12 of 31 days measured; a month needs 22. The others: 1 with no readings from the monitor, 4 with readings for part of the day (a day needs 18 hours), 14 with readings left out by our checks. |
| Feb 2025 | 11 of 28 days measured; a month needs 20. The others: 7 with no readings from the monitor, 5 with readings for part of the day (a day needs 18 hours), 5 with readings left out by our checks. |
| Jan 2025 | 4 of 31 days measured; a month needs 22. The others: 6 with readings for part of the day (a day needs 18 hours), 21 with readings left out by our checks. |
| Dec 2024 | 15 of 31 days measured; a month needs 22. The others: 2 with readings for part of the day (a day needs 18 hours), 14 with readings left out by our checks. |
| Aug 2024 | 8 of 31 days measured; a month needs 22. The others: 21 with no readings from the monitor, 2 with readings for part of the day (a day needs 18 hours). |
| Jul 2024 | No day measured. The others: 31 with no readings from the monitor. |
| Jun 2024 | 3 of 30 days measured; a month needs 21. The others: 27 with no readings from the monitor. |
| Sep 2023 | No day measured. The others: 30 with no readings from the monitor. |
| Aug 2023 | No day measured. The others: 31 with no readings from the monitor. |
| Jul 2023 | 21 of 31 days measured; a month needs 22. The others: 7 with no readings from the monitor, 2 with readings for part of the day (a day needs 18 hours), 1 missing from OpenAQ's archive. |
| Mar 2023 | 9 of 31 days measured; a month needs 22. The others: 2 with readings for part of the day (a day needs 18 hours), 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.
Laja's worst months
| Month | US AQI | World rank | Episode |
|---|---|---|---|
| June 2025 | 16373.2 µg/m³ | 6thof 2,508 | Southern Chile, 29 June to 4 July 2025 South-western Chile, June 2025 |
| May 2024 | 16169.9 µg/m³ | 12thof 2,684 | South-western Chile, 24 to 28 May 2024 South-western Chile, 14 to 19 May 2024 |
| June 2026 | 16068.8 µg/m³ | 16thof 2,497 | – |
| May 2026 | 15764.3 µg/m³ | 22ndof 2,874 | South-western Chile, May 2026 |
| July 2025 | 15561.6 µg/m³ | 15thof 2,889 | Southern Chile, 29 June to 4 July 2025 |
| June 2023 | 15055.2 µg/m³ | 14thof 1,603 | – |
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.
Laja's worst days
| Day | US AQI | Episode |
|---|---|---|
| 11 Jun 2025 | 234159.0 µg/m³ | South-western Chile, June 2025 |
| 30 Jun 2025 | 234159.0 µg/m³ | Southern Chile, 29 June to 4 July 2025 |
| 29 Jun 2026 | 229154.0 µg/m³ | – |
| 11 Jul 2023 | 220145.0 µg/m³ | – |
| 26 May 2024 | 217142.0 µg/m³ | South-western Chile, 24 to 28 May 2024 |
| 16 May 2024 | 208133.0 µg/m³ | South-western Chile, 14 to 19 May 2024 |
| 28 Jun 2026 | 203128.0 µg/m³ | – |
| 18 Jul 2023 | 202127.0 µg/m³ | Southern Chile, July 2023 |
| 24 Aug 2026 | 201126.0 µg/m³ | Southern Chile, August 2026 |
| 19 Jun 2023 | 200125.0 µg/m³ | – |
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, Laja, Chile, 1 Jan 2023 – 30 Sep 2026. Monitor data from Chile - SINCA via OpenAQ; sources listed at smogrank.com/sources. smogrank.com/cl/laja/history (accessed 12 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.
Laja now: the last 24 hours, its ranks today and the last 12 months day by day.
Updated 2026-10-12 20:07 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).