Anchorage Air Quality in Fall
Across 2019–2025, Anchorage's fall (September–November) air quality had a median AQI of 30 (Good) over 637 monitored days in the Anchorage, AK area. 0.2% of fall days (1 of 637) reached Unhealthy for Sensitive Groups or worse, and fine particulate matter (PM2.5) set the daily AQI on 83.0% of days. The cleanest fall on record here was 2022 (median AQI 19, 0 days above 100) and the worst was 2021 (median 29, 1 day above 100, peak AQI 107).
- Good: 76.8%
- Moderate: 23.1%
- Unhealthy for Sensitive Groups: 0.2%
- Unhealthy or worse: 0.0%
Improve Indoor Air Quality
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How is the air in Anchorage in fall?
Good on a typical day: median AQI 30 across 2019–2025, with 0.2% of fall days above AQI 100. Fine particulate matter (PM2.5) is the main driver.
- ✓76.8% of fall days were Good (AQI 0–50), 23.1% Moderate (51–100).
- ✓1 day of 637 reached AQI 101+; the fall peak was 107.
- ✓Cleanest month: October; worst month: September.
Frequently asked questions
What is the air quality like in Anchorage in fall?▾
Across 2019–2025, the median daily AQI in Anchorage in fall was 30 (Good). 76.8% of days were Good, 23.1% Moderate, and 0.2% reached Unhealthy for Sensitive Groups or worse, based on 637 monitored days in EPA's Air Quality System.
Is fall a good time for outdoor exercise in Anchorage?▾
A typical fall day in Anchorage sits in the Good range (median AQI 30), so running, cycling and children's outdoor play are fine for everyone on most days; fewer than 1% of fall days reached AQI 101+ in 2019–2025.
Which pollutant causes Anchorage's fall air quality problems?▾
Fine particulate matter (PM2.5) set the daily AQI on 83.0% of fall days in Anchorage. The highest fall AQI recorded in 2019–2025 was 107 (Unhealthy for Sensitive Groups), in 2021.
Anchorage fall air quality, year by year
Anchorage fall air quality by year (Anchorage, AK, EPA AQS daily AQI)
| Year | Days monitored | Median AQI | Days above 100 | Peak AQI | Main pollutant |
|---|---|---|---|---|---|
| 2019 | 91 | 28 | 0 | 97 | PM2.5 |
| 2020 | 91 | 38 | 0 | 82 | PM2.5 |
| 2021worst | 91 | 29 | 1 | 107 | PM2.5 |
| 2022cleanest | 91 | 19 | 0 | 77 | PM2.5 |
| 2023 | 91 | 27 | 0 | 83 | PM2.5 |
| 2024 | 91 | 32 | 0 | 90 | PM2.5 |
| 2025 | 91 | 36 | 0 | 71 | PM2.5 |
What fall air means in Anchorage
A typical fall day in Anchorage sits in the Good range (median AQI 30), so running, cycling and children's outdoor play are fine for everyone on most days; fewer than 1% of fall days reached AQI 101+ in 2019–2025.
Fall's median AQI of 30 is in line with Anchorage's whole-year median of 27, so this period is neither a clean nor a dirty stretch for the area. Nationally, the median Fall AQI across every EPA metro area (296,275 metro-days, 2019–2025) is 40, so Anchorage runs below the national Fall norm; 0.2% of its Fall days topped AQI 100 versus 1.5% nationally (below average).
Within the season, October is the cleanest month (median AQI 34, 0.0% of days above 100) and September the worst (median 21, 0.5% above 100).
Activity-specific thresholds: running, cycling, kids' sports.
Right now in Anchorage
The latest EPA AirNow observation puts Anchorage's AQI at 18 (PM10). The figures above are multi-year season statistics, not today's reading.
View current Anchorage air quality →Source: EPA Air Quality System (AQS) pre-generated Daily AQI by CBSA files — daily AQI by CBSA (Anchorage, AK), 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.