SmogRank / Chile / Biobio / Hualpén
Hualpén, month by month
Hualpén has a measured daily mean on 1,074 days since 1 January 2023. Its worst month was July 2024, at 172 US AQI (85.5 µg/m³), 2nd of 2,566 cities on that month's world ranking. Its cleanest was December 2023, at 70 US AQI (19.4 µg/m³). 2025 averaged 118 US AQI (42.3 µg/m³), against 119 US AQI (43.0 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
9 months
| Month | Why |
|---|---|
| Feb 2025 | No day measured. The others: 28 with under 18 hours of readings or readings that failed our checks. |
| Jan 2025 | 4 of 31 days measured; a month needs 22. The others: 27 with under 18 hours of readings or readings that failed our checks. |
| Dec 2024 | 17 of 31 days measured; a month needs 22. The others: 14 with under 18 hours of readings or readings that failed our checks. |
| Sep 2023 | No day measured. The others: 30 with under 18 hours of readings or readings that failed our checks. |
| Aug 2023 | No day measured. The others: 31 with under 18 hours of readings or readings that failed our checks. |
| Jul 2023 | 20 of 31 days measured; a month needs 22. The others: 1 missing from OpenAQ's archive, 10 with under 18 hours of readings or readings that failed our checks. |
| May 2023 | 19 of 31 days measured; a month needs 22. The others: 12 with under 18 hours of readings or readings that failed our checks. |
| Mar 2023 | 9 of 31 days measured; a month needs 22. The others: 20 missing from OpenAQ's archive, 2 with under 18 hours of readings or readings that failed our checks. |
| 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.
Hualpén's worst months
| Month | US AQI | World rank | Episode |
|---|---|---|---|
| July 2024 | 17285.5 µg/m³ | 2ndof 2,566 | Southern Chile, July 2024 South-western Chile, July 2024and 1 more |
| May 2024 | 17284.9 µg/m³ | 7thof 2,684 | South-western Chile, 24 to 28 May 2024 South-western Chile, 14 to 19 May 2024and 1 more |
| June 2025 | 16880.0 µg/m³ | 5thof 2,508 | – |
| June 2026 | 16271.6 µg/m³ | 13thof 2,497 | – |
| June 2023 | 16169.2 µg/m³ | 5thof 1,603 | Southern Chile, June 2023 |
| May 2025 | 15967.1 µg/m³ | 9thof 2,826 | – |
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.
Hualpén's worst days
| Day | US AQI | Episode |
|---|---|---|
| 20 May 2026 | 267192.0 µg/m³ | Southern Chile, May 2026 |
| 11 Jul 2024 | 246171.0 µg/m³ | Chile, July 2024 |
| 19 May 2024 | 242167.0 µg/m³ | South-western Chile, 14 to 19 May 2024 |
| 3 Jul 2026 | 237162.0 µg/m³ | Southern Chile, July 2026 |
| 18 Jul 2023 | 232157.0 µg/m³ | Southern Chile, July 2023 |
| 9 Jul 2024 | 227152.0 µg/m³ | – |
| 25 Jun 2024 | 224149.0 µg/m³ | Southern Chile, 24 to 25 June 2024 |
| 28 May 2024 | 223148.0 µg/m³ | South-western Chile, 24 to 28 May 2024 |
| 6 Jun 2025 | 217142.0 µg/m³ | – |
| 21 May 2025 | 215140.0 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, Hualpén, Chile, 1 Jan 2023 – 11 Oct 2026. Monitor data from Chile - SINCA via OpenAQ; sources listed at smogrank.com/sources. smogrank.com/cl/hualpen/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.
Hualpén now: the last 24 hours, its ranks today and the last 12 months day by day.
Updated 2026-10-12 21:07 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).