SmogRank / United States / California / Berkeley
Berkeley, month by month
Berkeley has a measured daily mean on 852 days since 9 January 2023. Its worst month was December 2024, at 61 US AQI (14.7 µg/m³), 491st of 2,616 cities on that month's world ranking. Its cleanest was April 2026, at 26 US AQI (4.6 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
19 months
| Month | Why |
|---|---|
| May 2026 | 15 of 31 days measured; a month needs 22. The others: 16 with under 18 hours of readings or readings that failed our checks. |
| Nov 2025 | 19 of 30 days measured; a month needs 21. The others: 11 with under 18 hours of readings or readings that failed our checks. |
| Sep 2024 | 19 of 30 days measured; a month needs 21. The others: 11 with under 18 hours of readings or readings that failed our checks. |
| Aug 2024 | 20 of 31 days measured; a month needs 22. The others: 11 with under 18 hours of readings or readings that failed our checks. |
| Apr 2024 | 13 of 30 days measured; a month needs 21. The others: 17 with under 18 hours of readings or readings that failed our checks. |
| Mar 2024 | No day measured. The others: 1 missing from OpenAQ's archive, 30 with under 18 hours of readings or readings that failed our checks. |
| Feb 2024 | 1 of 29 days measured; a month needs 21. The others: 28 with under 18 hours of readings or readings that failed our checks. |
| Jan 2024 | No day measured. The others: 31 with under 18 hours of readings or readings that failed our checks. |
| Dec 2023 | No day measured. The others: 31 with under 18 hours of readings or readings that failed our checks. |
| Nov 2023 | No day measured. The others: 30 with under 18 hours of readings or readings that failed our checks. |
| Oct 2023 | No day measured. The others: 31 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 | No day measured. The others: 1 missing from OpenAQ's archive, 30 with under 18 hours of readings or readings that failed our checks. |
| Jun 2023 | No day measured. The others: 30 with under 18 hours of readings or readings that failed our checks. |
| May 2023 | No day measured. The others: 31 with under 18 hours of readings or readings that failed our checks. |
| Apr 2023 | No day measured. The others: 3 missing from OpenAQ's archive, 27 with under 18 hours of readings or readings that failed our checks. |
| Mar 2023 | 12 of 31 days measured; a month needs 22. The others: 8 missing from OpenAQ's archive, 11 with under 18 hours of readings or readings that failed our checks. |
| Jan 2023 | 8 of 31 days measured; a month needs 22. The others: 15 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.
Berkeley's worst months
| Month | US AQI | World rank | Episode |
|---|---|---|---|
| December 2024 | 6114.7 µg/m³ | 491stof 2,616 | California and Oregon, United States, December 2024 |
| June 2024 | 5712.2 µg/m³ | 334thof 2,563 | – |
| January 2025 | 5611.6 µg/m³ | 769thof 2,474 | – |
| May 2024 | 5511.0 µg/m³ | 595thof 2,684 | – |
| June 2025 | 5410.8 µg/m³ | 1,068thof 2,508 | – |
| October 2025 | 5310.4 µg/m³ | 533rdof 2,614 | – |
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.
Berkeley's worst days
| Day | US AQI | Episode |
|---|---|---|
| 7 Dec 2024 | 9935.1 µg/m³ | California and Oregon, United States, December 2024 |
| 8 Dec 2024 | 9030.0 µg/m³ | California and Oregon, United States, December 2024 |
| 11 Dec 2024 | 8326.5 µg/m³ | California and Oregon, United States, December 2024 |
| 15 Mar 2025 | 7622.5 µg/m³ | – |
| 6 Jun 2024 | 7421.5 µg/m³ | – |
| 4 Dec 2024 | 7421.4 µg/m³ | California and Oregon, United States, December 2024 |
| 20 Dec 2024 | 7421.3 µg/m³ | – |
| 15 Jan 2026 | 7320.9 µg/m³ | – |
| 26 Sept 2025 | 7220.3 µg/m³ | – |
| 31 May 2024 | 7120.1 µg/m³ | – |
Daily means, the highest since 9 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, Berkeley, United States, 9 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/berkeley/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.
Berkeley 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).