Anchorage Air Quality in Winter
Across 2019–2025, Anchorage's winter (December–February) air quality had a median AQI of 44 (Good) over 632 monitored days in the Anchorage, AK area. 1.0% of winter days (6 of 632) reached Unhealthy for Sensitive Groups or worse, and fine particulate matter (PM2.5) set the daily AQI on 95.7% of days. The cleanest winter on record here was 2022 (median AQI 42, 0 days above 100) and the worst was 2021 (median 47, 3 days above 100, peak AQI 163).
- Good: 56.8%
- Moderate: 42.2%
- Unhealthy for Sensitive Groups: 0.8%
- Unhealthy or worse: 0.2%
Improve Indoor Air Quality
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How is the air in Anchorage in winter?
Good on a typical day: median AQI 44 across 2019–2025, with 1.0% of winter days above AQI 100. Fine particulate matter (PM2.5) is the main driver.
- ✓56.8% of winter days were Good (AQI 0–50), 42.2% Moderate (51–100).
- ✓6 days of 632 reached AQI 101+; the winter peak was 163.
- ✓Cleanest month: February; worst month: January.
Frequently asked questions
What is the air quality like in Anchorage in winter?▾
Across 2019–2025, the median daily AQI in Anchorage in winter was 44 (Good). 56.8% of days were Good, 42.2% Moderate, and 1.0% reached Unhealthy for Sensitive Groups or worse, based on 632 monitored days in EPA's Air Quality System.
Is winter a good time for outdoor exercise in Anchorage?▾
A typical winter day in Anchorage sits in the Good range (median AQI 44), so running, cycling and children's outdoor play are fine for everyone on most days; about 1 day in 100 of winter days (1.0%) reached AQI 101+ in 2019–2025.
Which pollutant causes Anchorage's winter air quality problems?▾
Fine particulate matter (PM2.5) set the daily AQI on 95.7% of winter days in Anchorage. The highest winter AQI recorded in 2019–2025 was 163 (Unhealthy), in 2021.
Anchorage winter air quality, year by year
Anchorage winter air quality by year (Anchorage, AK, EPA AQS daily AQI)
| Year | Days monitored | Median AQI | Days above 100 | Peak AQI | Main pollutant |
|---|---|---|---|---|---|
| 2019 | 90 | 54 | 0 | 95 | PM2.5 |
| 2020 | 91 | 48 | 1 | 103 | PM2.5 |
| 2021worst | 90 | 47 | 3 | 163 | PM2.5 |
| 2022cleanest | 90 | 42 | 0 | 96 | PM2.5 |
| 2023 | 90 | 39 | 1 | 102 | PM2.5 |
| 2024 | 91 | 43 | 0 | 95 | PM2.5 |
| 2025 | 90 | 43 | 1 | 106 | PM2.5 |
What winter air means in Anchorage
A typical winter day in Anchorage sits in the Good range (median AQI 44), so running, cycling and children's outdoor play are fine for everyone on most days; about 1 day in 100 of winter days (1.0%) reached AQI 101+ in 2019–2025.
Winter's median AQI of 44 is above Anchorage's whole-year median of 27, making it one of the area's dirtier periods. Nationally, the median Winter AQI across every EPA metro area (278,620 metro-days, 2019–2025) is 40, so Anchorage runs above the national Winter norm; 1.0% of its Winter days topped AQI 100 versus 0.6% nationally (about the same).
Within the season, February is the cleanest month (median AQI 33, 0.0% of days above 100) and January the worst (median 53, 2.8% 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.