SmogRank / United States / California / Compton
Compton, month by month
Compton has a measured daily mean on 1,255 days since 1 January 2023. Its worst month was December 2024, at 78 US AQI (23.5 µg/m³), 164th of 2,616 cities on that month's world ranking. Its cleanest was March 2025, at 41 US AQI (7.4 µg/m³). 2025 averaged 57 US AQI (12.4 µg/m³), against 57 US AQI (12.1 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
4 months
| Month | Why |
|---|---|
| Jul 2024 | 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 | 1 of 28 days measured; a month needs 20. The others: 25 missing from OpenAQ's archive, 2 with under 18 hours of readings or readings that failed our checks. |
| Jan 2023 | 19 of 31 days measured; a month needs 22. The others: 6 missing from OpenAQ's archive, 6 with under 18 hours of readings or readings that failed our checks. |
A day counts once 18 hours of it are measured; a month needs 70% of its days.
Compton's worst months
| Month | US AQI | World rank | Episode |
|---|---|---|---|
| December 2024 | 7823.5 µg/m³ | 164thof 2,616 | South-western United States and Mexico, December 2024 to January 2025 California, United States, December 2024and 1 more |
| January 2025 | 7421.4 µg/m³ | 255thof 2,474 | California, United States, January 2025 South-western United States and Mexico, December 2024 to January 2025 |
| December 2025 | 7220.6 µg/m³ | 486thof 3,006 | Western United States and Mexico, December 2025 |
| December 2023 | 6717.8 µg/m³ | 205thof 2,247 | Western United States and Mexico, December 2023 |
| November 2025 | 6416.2 µg/m³ | 542ndof 2,715 | California, United States, November 2025 |
| July 2023 | 6114.7 µg/m³ | 155thof 1,432 | California, United States, July 2023 |
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.
Compton's worst days
| Day | US AQI | Episode |
|---|---|---|
| 25 Dec 2023 | 14151.9 µg/m³ | Western United States and Mexico, December 2023 |
| 9 Jan 2025 | 14151.7 µg/m³ | – |
| 1 Jan 2025 | 13950.9 µg/m³ | South-western United States and Mexico, December 2024 to January 2025 |
| 8 Jan 2025 | 13448.8 µg/m³ | – |
| 10 Jan 2025 | 13147.7 µg/m³ | – |
| 5 Jul 2025 | 13047.2 µg/m³ | – |
| 13 Dec 2025 | 13047.1 µg/m³ | Western United States and Mexico, December 2025 |
| 4 Jul 2025 | 12746.1 µg/m³ | – |
| 31 Dec 2024 | 12746.0 µg/m³ | South-western United States and Mexico, December 2024 to January 2025 |
| 17 Dec 2025 | 12545.4 µg/m³ | Western United States and Mexico, December 2025 |
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, Compton, United States, 1 Jan 2023 – 11 Oct 2026. Monitor data from AirNow, via OpenAQ and from the publisher directly; sources listed at smogrank.com/sources. smogrank.com/us/compton/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.
Compton now: the last 24 hours, its ranks today and the last 12 months day by day.
Updated 2026-10-12 17:07 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).