SmogRank / Canada / British Columbia / Fort St. John
Fort St. John, month by month
Fort St. John has a measured daily mean on 1,227 days since 1 January 2023. Its worst month was May 2023, at 135 US AQI (49.5 µg/m³), 14th of 1,600 cities on that month's world ranking. Its cleanest was October 2025, at 18 US AQI (3.3 µg/m³). 2025 averaged 38 US AQI (6.9 µg/m³), against 41 US AQI (7.3 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 |
|---|---|
| Aug 2024 | 10 of 31 days measured; a month needs 22. The others: 21 with under 18 hours of readings or readings that failed our checks. |
| Jun 2023 | 20 of 30 days measured; a month needs 21. 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 | 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.
Fort St. John's worst months
| Month | US AQI | World rank | Episode |
|---|---|---|---|
| May 2023 | 13549.5 µg/m³ | 14thof 1,600 | North-western United States and Canada, May 2023 North-western Canada and United States, May 2023and 1 more |
| September 2023 | 11541.3 µg/m³ | 14thof 2,176 | Alberta, Saskatchewan and British Columbia, Canada, September 2023 Alberta, British Columbia and Saskatchewan, Canada, September 2023and 1 more |
| July 2023 | 10035.4 µg/m³ | 33rdof 1,432 | United States and Canada, July 2023 North-western Canada and United States, July 2023and 2 more |
| July 2024 | 9231.1 µg/m³ | 57thof 2,566 | North-western United States and Canada, July 2024 |
| August 2023 | 7723.1 µg/m³ | 95thof 1,980 | Northern United States and Canada, August and September 2023 North-western United States and Canada, August 2023 |
| June 2025 | 6516.6 µg/m³ | 337thof 2,508 | North-western Canada and United States, June 2025 |
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.
Fort St. John's worst days
| Day | US AQI | Episode |
|---|---|---|
| 19 Jul 2024 | 459305.0 µg/m³ | North-western United States and Canada, July 2024 |
| 19 May 2023 | 298223.0 µg/m³ | North-western United States and Canada, May 2023 Northern United States and Canada, May 2023 |
| 20 May 2023 | 271196.0 µg/m³ | North-western United States and Canada, May 2023 |
| 18 May 2023 | 242167.0 µg/m³ | Northern United States and Canada, May 2023 |
| 2 Sept 2023 | 230155.0 µg/m³ | Northern United States and Canada, August and September 2023 |
| 25 Sept 2023 | 224149.0 µg/m³ | – |
| 10 Jul 2023 | 221146.0 µg/m³ | Alberta, British Columbia and Saskatchewan, Canada, July 2023 |
| 20 Jul 2024 | 221146.0 µg/m³ | North-western United States and Canada, July 2024 |
| 12 Sept 2023 | 219144.0 µg/m³ | Alberta, British Columbia and Saskatchewan, Canada, September 2023 |
| 1 Sept 2025 | 215140.0 µg/m³ | North-western United States and Canada, August and September 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, Fort St. John, Canada, 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/ca/fort-st-john/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.
Fort St. John now: the last 24 hours, its ranks today and the last 12 months day by day.
Updated 2026-10-12 22:07 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).