SmogRank / United States / California / Big Bear City
Big Bear City, month by month
Big Bear City has a measured daily mean on 1,104 days since 1 January 2023. Its worst month was September 2024, at 86 US AQI (27.7 µg/m³), 63rd of 2,010 cities on that month's world ranking. Its cleanest was September 2026, at 15 US AQI (2.7 µg/m³). 2024 averaged 44 US AQI (7.9 µg/m³), against 39 US AQI (7.0 µg/m³) in 2023.
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
11 months
| Month | Why |
|---|---|
| Nov 2025 | 18 of 30 days measured; a month needs 21. The others: 1 with no readings from the monitor, 11 with readings for part of the day (a day needs 18 hours). |
| Jun 2025 | No day measured. The others: 21 with no readings from the monitor, 9 with readings for part of the day (a day needs 18 hours). |
| May 2025 | No day measured. The others: 23 with no readings from the monitor, 8 with readings for part of the day (a day needs 18 hours). |
| Apr 2025 | No day measured. The others: 23 with no readings from the monitor, 7 with readings for part of the day (a day needs 18 hours). |
| Mar 2025 | No day measured. The others: 31 with no readings from the monitor. |
| Feb 2025 | 12 of 28 days measured; a month needs 20. The others: 15 with no readings from the monitor, 1 with readings for part of the day (a day needs 18 hours). |
| Dec 2024 | 21 of 31 days measured; a month needs 22. The others: 4 with no readings from the monitor, 6 with readings for part of the day (a day needs 18 hours). |
| Nov 2024 | 10 of 30 days measured; a month needs 21. The others: 19 with no readings from the monitor, 1 with readings for part of the day (a day needs 18 hours). |
| May 2024 | 15 of 31 days measured; a month needs 22. The others: 11 with no readings from the monitor, 5 with readings for part of the day (a day needs 18 hours). |
| Mar 2023 | 11 of 31 days measured; a month needs 22. The others: 20 missing from OpenAQ's archive. |
| Feb 2023 | No day measured. The others: 2 with no readings from the monitor, 1 with readings for part of the day (a day needs 18 hours), 25 missing from OpenAQ's archive. |
A day counts once 18 hours of it are measured; a month needs 70% of its days.
Big Bear City's worst months
| Month | US AQI | World rank |
|---|---|---|
| September 2024 | 8627.7 µg/m³ | 63rdof 2,010 |
| December 2023 | 5812.7 µg/m³ | 379thof 2,247 |
| December 2025 | 5410.7 µg/m³ | 1,190thof 3,006 |
| November 2023 | 529.7 µg/m³ | 696thof 2,243 |
| January 2026 | 529.4 µg/m³ | 1,173rdof 2,617 |
| February 2026 | 519.1 µg/m³ | 1,638thof 2,866 |
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.
Big Bear City's worst days
| Day | US AQI |
|---|---|
| 14 Sept 2024 | 17792.6 µg/m³ |
| 10 Sept 2024 | 17691.5 µg/m³ |
| 9 Sept 2024 | 16980.9 µg/m³ |
| 15 Sept 2024 | 16169.9 µg/m³ |
| 8 Sept 2024 | 15256.5 µg/m³ |
| 28 Sept 2024 | 13348.6 µg/m³ |
| 12 Sept 2024 | 12846.3 µg/m³ |
| 29 Sept 2024 | 9331.7 µg/m³ |
| 7 Sept 2024 | 9130.5 µg/m³ |
| 16 Sept 2024 | 8225.8 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, Big Bear City, 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/big-bear-city/history (accessed 13 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.
Big Bear City now: the last 24 hours, its ranks today and the last 12 months day by day.
Updated 2026-10-13 01:07 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).