Median AQI
24
Good
Alaska · County air quality · 2025
Anchorage County, Alaska
Median AQI 24 (Good). 80.8% of monitored days rated Good, direct from EPA Air Quality System stations.
- 24
- Median AQI
- 80.8%
- Good-air days
- 0
- Unhealthy days
- 54%
- Cleaner than US counties
The verdict
According to EPA Air Quality System monitoring data, Anchorage County's air is good on balance, cleaner than the median US county, a median AQI of 24 with 80.8% of 182 monitored days in the Good band, driven mainly by PM10.
- 24
- median AQI · Good
- 80.8%
- days rated Good
- PM10
- main pollutant
- 54%
- cleaner than US counties
Not one day crossed into the Unhealthy tier; the worst single reading was AQI 110.
Data updated July 2026
- Good · 147 d · 80.8%
- Moderate · 34 d · 18.7%
- USG · 1 d · 0.5%
How did Anchorage County's air break down in 2025?
Across 182 monitored days, 147 fell in the Good band (AQI 0–50) and 0 reached Unhealthy or worse. The worst single day peaked at AQI 110 (USG).
EPA AQS →Air quality data from EPA Air Quality System (2025). 182 days monitored. Median AQI: 24 (Good).
Insights: Anchorage County, Alaska. EPA monitors recorded a median Air Quality Index of 24 across 182 measured days in 2025, earning a Good classification and a Good health grade. Of those days, 147 (81%) fell in the Good band (AQI 0–50), 34 (19%) registered Moderate readings, and 1 (1%) reached Unhealthy for Sensitive Groups. The 90th-percentile AQI settled at 61, while the worst single-day peak hit 110 (USG). Residents averaged about 24.2 clean-air days per 30-day window during the monitoring year.
The full pollutant mix ranks as PM10 (108 days), PM2.5 (70 days), CO (4 days). Across the 2020–2025 trend window, good days shifted by -147 and the median AQI moved -3 points, placing the multi-year trajectory at stable. The worst single reading over the 2020–2025 window was AQI 110, usg but never Unhealthy. Nearby counties show comparable readings: Aleutians East (95.0% good, AQI 11); Denali (100.0% good, AQI 38); Fairbanks North Star (61.5% good, AQI 42); Juneau (85.1% good, AQI 21); Kenai Peninsula (100.0% good, AQI 8); Matanuska-Susitna (90.3% good, AQI 7).
Air Quality Summary
Good Days
80.8%
147 of 182 monitored days
5.8pp vs 75% target
Max AQI Recorded
110
USG
Health Grade
Good
90th-pct AQI 61
Anchorage County, Good days share 80.8%
National avg
Share of monitored days at AQI 0-50 (Good band).
Anchorage County, Unhealthy-or-worse share 0.0%
National avg
Share of monitored days above AQI 150 (Unhealthy or worse). Bar maxes at 10% (worst-county ceiling).
AQI Day Breakdown (2025)
Distribution of 182 monitored days across EPA AQI categories.
Good
147
81%
Moderate
34
19%
USG
1
1%
Unhealthy
0
0%
Very Unhealthy
0
0%
Hazardous
0
0%
Pollutant Breakdown
Days where each pollutant was the primary driver of AQI readings in Anchorage County.
- PM10 · 108 days · 59.3%
- PM2.5 · 70 days · 38.5%
- CO · 4 days · 2.2%
Health Impact Assessment
Good
Anchorage County's air quality is rated Good based on 80.8% good air days. No unhealthy air days were recorded in 2025.
Air quality was acceptable on 80.8% of monitored days in 2025, with a median AQI of 24. Unusually sensitive people can check real-time conditions at AirNow.gov during high-pollution events.
The dominant pollutant is PM10, driving AQI on 108 of 182 monitored days.
5-Year Air Quality Trend
Air quality is stable in Anchorage County. Best year: 2023 (319 good days).
| Year | Good | Moderate | USG | Unhealthy | Median AQI | Max AQI |
|---|---|---|---|---|---|---|
| 2020 | 294 | 72 | 0 | 0 | 27 | 92 |
| 2021 | 289 | 74 | 2 | 0 | 28 | 132 |
| 2022 | 302 | 62 | 1 | 0 | 24 | 125 |
| 2023 | 319 | 46 | 0 | 0 | 21 | 71 |
| 2024 | 297 | 69 | 0 | 0 | 24 | 90 |
| 2025 | 147 | 34 | 1 | 0 | 24 | 110 |
How does Anchorage County compare?
How Anchorage County compares
Good-day share better than US avg
Anchorage County 80.8%
Aleutians East County, Alaska 95.0%
US average 76.5%
Median AQI better than US avg
Anchorage County 24
Aleutians East County, Alaska 11
US average 38
Unhealthy days / yr about average
Anchorage County 0
Aleutians East County, Alaska 0
US average 0
Other Counties in Alaska
Air quality comparison for nearby counties in Alaska.
Counties with Similar Air Quality
Counties across the US with a similar median AQI to Anchorage County.
Alamosa County, Colorado
AQI 24 · 90.8% good
Charlton County, Georgia
AQI 24 · 79.0% good
Crook County, Oregon
AQI 24 · 80.7% good
Culberson County, Texas
AQI 24 · 80.0% good
Kootenai County, Idaho
AQI 24 · 88.4% good
Lake County, Oregon
AQI 24 · 82.8% good
What Anchorage County's air means for you
The air here stays in the breathable range year-round, with PM10 the main thing to watch.
- Sensitive groups (asthma, heart conditions, children, older adults) should check the AQI on high-PM10 days, the guide explains what a median of 24 means for exposure. Health guidance
- See how Anchorage County ranks against every monitored U.S. county on Good-day share. County rankings
- Compare Anchorage County with its Alaska neighbours before drawing a conclusion about the region. All of Alaska
Based on 182 EPA-monitored days in 2025; figures reflect only days the monitors reported. Source: EPA Air Quality System annual summaries.
More Air Quality Data
Air Quality Guides
Frequently Asked Questions
What is the air quality in Anchorage County, Alaska? ▼
Anchorage County has a median Air Quality Index (AQI) of 24, rated "Good." 80.8% of monitored days (147 out of 182) had good air quality in 2025.
What is the main pollutant in Anchorage County? ▼
The primary pollutant in Anchorage County is Coarse Particles (PM10), which was the main AQI driver on 108 days (59% of monitored days). Irritates airways and can aggravate asthma and bronchitis.
How many unhealthy air days does Anchorage County have? ▼
In 2025, Anchorage County recorded 0 unhealthy air days (0 Unhealthy, 0 Very Unhealthy, 0 Hazardous). The maximum AQI reached 110.
Is the air quality in Anchorage County getting better or worse? ▼
Air quality in Anchorage County is stable based on 5-year trends (2020-2025). Best year: 2023 with 319 good days. Worst year: 2025 with 147 good days.
What does AQI 24 mean for health? ▼
Anchorage County's median AQI of 24 falls in the "Good" category. See the <a href="/guides/understanding-aqi" class="underline">AQI category guide</a> for what each range means for health.
How does Anchorage County compare to other counties in Alaska? ▼
Anchorage County has 80.8% good air days. Nearby counties in Alaska: Aleutians East (95.0% good), Denali (100.0% good), Fairbanks North Star (61.5% good), Juneau (85.1% good), Kenai Peninsula (100.0% good), Matanuska-Susitna (90.3% good).
What is the 90th percentile AQI in Anchorage County? ▼
The 90th percentile AQI for Anchorage County is 61, meaning 90% of monitored days had an AQI at or below this level. The maximum AQI recorded was 110 (USG).
Data Sources
Primary Source: U.S. Environmental Protection Agency (EPA), Air Quality System (AQS), Annual AQI by County dataset, 2020–2025 (aqs.epa.gov). For current conditions (not shown here — this page is historical annual data), see EPA AirNow (airnow.gov). See our methodology for how AQI, median, and coverage figures are computed.
Informational only, not professional advice. Data from EPA AQS. See our disclaimer.
Every figure on PlainAir is rendered directly from EPA AQS air-quality monitoring data, no number is typed in by an editor. This page draws directly on EPA AQS air-quality monitoring data, no figure is typed in by an editor. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error.