Seattle Air Quality in November
Across 2019–2025, Seattle's November air quality had a median AQI of 54 (Moderate) over 210 monitored days in the Seattle-Tacoma-Bellevue, WA area. 1.9% of November days (4 of 210) reached Unhealthy for Sensitive Groups or worse, and fine particulate matter (PM2.5) set the daily AQI on 83.8% of days. The cleanest November on record here was 2024 (median AQI 47, 0 days above 100) and the worst was 2022 (median 65, 4 days above 100, peak AQI 110).
- Good: 33.3%
- Moderate: 64.8%
- Unhealthy for Sensitive Groups: 1.9%
- Unhealthy or worse: 0.0%
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How is the air in Seattle in November?
Moderate on a typical day: median AQI 54 across 2019–2025, with 1.9% of November days above AQI 100. Fine particulate matter (PM2.5) is the main driver.
- ✓33.3% of November days were Good (AQI 0–50), 64.8% Moderate (51–100).
- ✓4 days of 210 reached AQI 101+; the November peak was 110.
- ✓Best November: 2024; worst November: 2022.
Frequently asked questions
What is the air quality like in Seattle in November?▾
Across 2019–2025, the median daily AQI in Seattle in November was 54 (Moderate). 33.3% of days were Good, 64.8% Moderate, and 1.9% reached Unhealthy for Sensitive Groups or worse, based on 210 monitored days in EPA's Air Quality System.
Is November a good time for outdoor exercise in Seattle?▾
A typical November day in Seattle is Moderate (median AQI 54): outdoor exercise is acceptable for most people, but unusually sensitive individuals should watch for symptoms, and about 1 day in 53 of November days (1.9%) reached AQI 101+ — the level at which EPA advises people with asthma, children and older adults to shorten hard outdoor exertion.
Which pollutant causes Seattle's November air quality problems?▾
Fine particulate matter (PM2.5) set the daily AQI on 83.8% of November days in Seattle. The highest November AQI recorded in 2019–2025 was 110 (Unhealthy for Sensitive Groups), in 2022.
Seattle November air quality, year by year
Seattle November air quality by year (Seattle-Tacoma-Bellevue, WA, EPA AQS daily AQI)
| Year | Days monitored | Median AQI | Days above 100 | Peak AQI | Main pollutant |
|---|---|---|---|---|---|
| 2019 | 30 | 63 | 0 | 94 | PM2.5 |
| 2020 | 30 | 53 | 0 | 87 | PM2.5 |
| 2021 | 30 | 51 | 0 | 88 | PM2.5 |
| 2022worst | 30 | 65 | 4 | 110 | PM2.5 |
| 2023 | 30 | 63 | 0 | 92 | PM2.5 |
| 2024cleanest | 30 | 47 | 0 | 74 | PM2.5 |
| 2025 | 30 | 52 | 0 | 73 | PM2.5 |
What November air means in Seattle
A typical November day in Seattle is Moderate (median AQI 54): outdoor exercise is acceptable for most people, but unusually sensitive individuals should watch for symptoms, and about 1 day in 53 of November days (1.9%) reached AQI 101+ — the level at which EPA advises people with asthma, children and older adults to shorten hard outdoor exertion.
November's median AQI of 54 is above Seattle's whole-year median of 49, making it one of the area's dirtier periods. Nationally, the median November AQI across every EPA metro area (92,704 metro-days, 2019–2025) is 39, so Seattle runs above the national November norm; 1.9% of its November days topped AQI 100 versus 0.6% nationally (above average).
November is part of Seattle's fall season (September, October, November); the fall page pools all three months.
Activity-specific thresholds: running, cycling, kids' sports.
Right now in Seattle
The latest EPA AirNow observation puts Seattle's AQI at 37 (PM2.5). The figures above are multi-year month statistics, not today's reading.
View current Seattle air quality →Source: EPA Air Quality System (AQS) pre-generated Daily AQI by CBSA files — daily AQI by CBSA (Seattle-Tacoma-Bellevue, WA), 2019–2025. Daily AQI per CBSA is the highest AQI reported by any monitor in the area that day; the defining parameter is the pollutant that set it. Month and season statistics pool every such day in the period across all years listed. Retrieved 2026-09-09.