SmogRank / United States / California / Crescent City
Crescent City, month by month
Crescent City, California has a measured daily mean on 1,050 days since 1 January 2023. Its worst month was August 2023, at 64 US AQI (15.9 µg/m³), 179th of 1,980 cities on that month's world ranking. Its cleanest was August 2025, at 27 US AQI (4.9 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
12 months
| Month | Why |
|---|---|
| Sep 2026 | 18 of 30 days measured; a month needs 21. The others: 6 with no readings from the monitor, 6 with readings for part of the day (a day needs 18 hours). |
| Jan 2026 | 2 of 31 days measured; a month needs 22. The others: 28 with no readings from the monitor, 1 with readings for part of the day (a day needs 18 hours). |
| Jul 2025 | 19 of 31 days measured; a month needs 22. The others: 10 with no readings from the monitor, 2 with readings for part of the day (a day needs 18 hours). |
| Nov 2024 | 19 of 30 days measured; a month needs 21. The others: 8 with no readings from the monitor, 3 with readings for part of the day (a day needs 18 hours). |
| Aug 2024 | 12 of 31 days measured; a month needs 22. The others: 17 with no readings from the monitor, 2 with readings for part of the day (a day needs 18 hours). |
| Jul 2024 | 14 of 31 days measured; a month needs 22. The others: 16 with no readings from the monitor, 1 with readings for part of the day (a day needs 18 hours). |
| Mar 2024 | 19 of 31 days measured; a month needs 22. The others: 7 with no readings from the monitor, 4 with readings for part of the day (a day needs 18 hours), 1 missing from OpenAQ's archive. |
| Feb 2024 | No day measured. The others: 28 with no readings from the monitor, 1 missing from OpenAQ's archive. |
| Jan 2024 | 16 of 31 days measured; a month needs 22. The others: 14 with no readings from the monitor, 1 with readings for part of the day (a day needs 18 hours). |
| Oct 2023 | 1 of 31 days measured; a month needs 22. The others: 29 with no readings from the monitor, 1 with readings for part of the day (a day needs 18 hours). |
| Mar 2023 | 8 of 31 days measured; a month needs 22. The others: 3 with readings for part of the day (a day needs 18 hours), 20 missing from OpenAQ's archive. |
| Feb 2023 | 1 of 28 days measured; a month needs 20. The others: 2 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.
Crescent City's worst months
| Month | US AQI | World rank | Episode |
|---|---|---|---|
| August 2023 | 6415.9 µg/m³ | 179thof 1,980 | North-western United States and Canada, August 2023 |
| September 2023 | 5913.3 µg/m³ | 245thof 2,176 | California and Oregon, United States, September 2023 Oregon and California, United States, September 2023 |
| November 2025 | 509.0 µg/m³ | 1,251stof 2,715 | – |
| December 2024 | 478.5 µg/m³ | 1,212thof 2,616 | – |
| May 2024 | 448.0 µg/m³ | 1,314thof 2,684 | – |
| February 2025 | 437.7 µg/m³ | 1,664thof 2,633 | – |
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.
Crescent City's worst days
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, Crescent City, California, 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/crescent-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.
Crescent 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).