SmogRank / Chile / Biobio / Hualqui
Hualqui, month by month
Hualqui has a measured daily mean on 1,201 days since 1 January 2023. Its worst month was July 2024, at 161 US AQI (69.6 µg/m³), 12th of 2,566 cities on that month's world ranking. Its cleanest was December 2025, at 58 US AQI (13.1 µg/m³). 2025 averaged 90 US AQI (29.8 µg/m³), against 93 US AQI (31.9 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
5 months
| Month | Why |
|---|---|
| Apr 2025 | 18 of 30 days measured; a month needs 21. The others: 12 with under 18 hours of readings or readings that failed our checks. |
| May 2024 | 8 of 31 days measured; a month needs 22. The others: 23 with under 18 hours of readings or readings that failed our checks. |
| 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.
Hualqui's worst months
| Month | US AQI | World rank | Episode |
|---|---|---|---|
| July 2024 | 16169.6 µg/m³ | 12thof 2,566 | Southern Chile, July 2024 South-western Chile, July 2024 |
| May 2026 | 15561.3 µg/m³ | 31stof 2,874 | Southern Chile, May 2026 |
| June 2025 | 15156.1 µg/m³ | 27thof 2,508 | Southern Chile, 29 June to 4 July 2025 Southern Chile, 2 to 4 June 2025 |
| July 2025 | 13549.5 µg/m³ | 35thof 2,889 | Southern Chile, 29 June to 4 July 2025 |
| June 2026 | 13549.2 µg/m³ | 52ndof 2,497 | – |
| May 2023 | 13147.7 µg/m³ | 17thof 1,600 | – |
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.
Hualqui's worst days
| Day | US AQI | Episode |
|---|---|---|
| 24 Jul 2024 | 186106.0 µg/m³ | – |
| 26 May 2024 | 184102.0 µg/m³ | South-western Chile, 24 to 28 May 2024 |
| 30 Jul 2024 | 184102.0 µg/m³ | Southern Chile, July 2024 |
| 20 May 2026 | 184102.0 µg/m³ | Southern Chile, May 2026 |
| 3 Jul 2025 | 18198.1 µg/m³ | Southern Chile, 29 June to 4 July 2025 |
| 3 Jun 2025 | 18197.8 µg/m³ | Southern Chile, 2 to 4 June 2025 |
| 4 Jun 2024 | 17994.9 µg/m³ | – |
| 21 Jun 2023 | 17894.7 µg/m³ | – |
| 5 Jul 2024 | 17893.9 µg/m³ | – |
| 23 Jul 2024 | 17893.9 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, Hualqui, Chile, 1 Jan 2023 – 11 Oct 2026. Monitor data from Chile - SINCA via OpenAQ; sources listed at smogrank.com/sources. smogrank.com/cl/hualqui/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.
Hualqui 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).