Anchorage Best & Worst AQI Days: Air Quality Guide
The worst air quality day on record for Anchorage (Anchorage, AK area) was January 1, 2021, when the daily AQI reached 163 (Unhealthy), set by fine particulate matter (PM2.5). Across 2,557 monitored days in 2019–2025, 5 of the 10 worst days were Unhealthy (AQI 151+) or worse; 9 of the 10 were driven by fine particulate matter (PM2.5) and 1 by coarse dust (PM10), and 7 of them fell in 2019. The cleanest day was January 25, 2025 at AQI 2 (Good); the 10 best days span 4 different years.
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When were Anchorage's worst and best air quality days?
Worst: January 1, 2021, AQI 163 (Unhealthy, PM2.5). Best: January 25, 2025, AQI 2 (Good). Based on 2,557 EPA-monitored days in the Anchorage, AK area, 2019–2025.
- ✓5 of the 10 worst days were Unhealthy (AQI 151+) or worse; the 10th-worst was AQI 125 (Unhealthy for Sensitive Groups).
- ✓Fine particulate matter (PM2.5) drove 9 of the 10 worst days.
- ✓2019 accounts for 7 of the 10 worst days.
Frequently asked questions
What was the worst air quality day in Anchorage?▾
January 1, 2021: the Anchorage, AK area's daily AQI hit 163 (Unhealthy), driven by fine particulate matter (PM2.5). That is the highest of 2,557 monitored days in 2019–2025.
What was the best air quality day in Anchorage?▾
January 25, 2025, with a daily AQI of 2 (Good). The daily AQI is the highest reading from any monitor in the area, so even the cleanest day reflects the area's worst monitor.
What was Anchorage's worst air quality day in 2025?▾
April 16, 2025, AQI 141 (Unhealthy for Sensitive Groups), set by coarse dust (PM10).
Which pollutant causes Anchorage's worst air days?▾
Fine particulate matter (PM2.5) set the AQI on 9 of the 10 worst days; coarse dust (PM10) on 1. The tables above list the defining pollutant for every day.
Anchorage's 10 worst air quality days, 2019–2025
Highest daily AQI recorded for the Anchorage, AK area (EPA AQS). The daily AQI is the highest reading from any monitor in the area that day.
| # | Date | AQI | Category | Defining pollutant |
|---|---|---|---|---|
| 1 | (2021 page) | 163 | Unhealthy | PM2.5 — fine particulate matter (PM2.5) |
| 2 | (2019 page) | 163 | Unhealthy | PM2.5 — fine particulate matter (PM2.5), in wildfire smoke season |
| 3 | (2019 page) | 158 | Unhealthy | PM2.5 — fine particulate matter (PM2.5), in wildfire smoke season |
| 4 | (2019 page) | 157 | Unhealthy | PM2.5 — fine particulate matter (PM2.5), in wildfire smoke season |
| 5 | (2019 page) | 152 | Unhealthy | PM2.5 — fine particulate matter (PM2.5), in wildfire smoke season |
| 6 | (2025 page) | 141 | Unhealthy for Sensitive Groups | PM10 — coarse dust (PM10) |
| 7 | (2019 page) | 138 | Unhealthy for Sensitive Groups | PM2.5 — fine particulate matter (PM2.5), in wildfire smoke season |
| 8 | (2019 page) | 136 | Unhealthy for Sensitive Groups | PM2.5 — fine particulate matter (PM2.5), in wildfire smoke season |
| 9 | (2019 page) | 127 | Unhealthy for Sensitive Groups | PM2.5 — fine particulate matter (PM2.5), in wildfire smoke season |
| 10 | (2022 page) | 125 | Unhealthy for Sensitive Groups | PM2.5 — fine particulate matter (PM2.5), in wildfire smoke season |
Worst day of each year in Anchorage
The single highest-AQI day in each year on record. Click a year for its full month-by-month statistics.
| Year | Worst day | AQI | Category | Defining pollutant |
|---|---|---|---|---|
| 2019 | 163 | Unhealthy | PM2.5 — fine particulate matter (PM2.5), in wildfire smoke season | |
| 2020 | 103 | Unhealthy for Sensitive Groups | PM2.5 — fine particulate matter (PM2.5) | |
| 2021 | 163 | Unhealthy | PM2.5 — fine particulate matter (PM2.5) | |
| 2022 | 125 | Unhealthy for Sensitive Groups | PM2.5 — fine particulate matter (PM2.5), in wildfire smoke season | |
| 2023 | 102 | Unhealthy for Sensitive Groups | PM2.5 — fine particulate matter (PM2.5) | |
| 2024 | 95 | Moderate | PM2.5 — fine particulate matter (PM2.5) | |
| 2025 | 141 | Unhealthy for Sensitive Groups | PM10 — coarse dust (PM10) |
Anchorage's 10 best air quality days, 2019–2025
Lowest daily AQI recorded for the Anchorage, AK area. Ties are listed most recent first.
| # | Date | AQI | Category | Defining pollutant |
|---|---|---|---|---|
| 1 | (2025 page) | 2 | Good | PM2.5 — fine particulate matter (PM2.5) |
| 2 | (2024 page) | 2 | Good | CO — carbon monoxide |
| 3 | (2023 page) | 2 | Good | CO — carbon monoxide |
| 4 | (2025 page) | 3 | Good | CO — carbon monoxide |
| 5 | (2025 page) | 3 | Good | PM10 — coarse dust (PM10) |
| 6 | (2024 page) | 3 | Good | PM10 — coarse dust (PM10) |
| 7 | (2023 page) | 3 | Good | PM10 — coarse dust (PM10) |
| 8 | (2023 page) | 3 | Good | CO — carbon monoxide |
| 9 | (2022 page) | 3 | Good | PM10 — coarse dust (PM10) |
| 10 | (2022 page) | 3 | Good | PM10 — coarse dust (PM10) |
Right now in Anchorage
The latest EPA AirNow observation puts Anchorage's AQI at 18 (PM10). The days above are historical records, 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.