Washington Air Quality in August
Across 2019–2025, Washington's August air quality had a median AQI of 54 (Moderate) over 217 monitored days in the Washington-Arlington-Alexandria, DC-VA-MD-WV area. 3.7% of August days (8 of 217) reached Unhealthy for Sensitive Groups or worse, and ground-level ozone set the daily AQI on 59.0% of days. The cleanest August on record here was 2025 (median AQI 46, 0 days above 100) and the worst was 2019 (median 59, 3 days above 100, peak AQI 122).
- Good: 40.6%
- Moderate: 55.8%
- Unhealthy for Sensitive Groups: 3.7%
- Unhealthy or worse: 0.0%
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How is the air in Washington in August?
Moderate on a typical day: median AQI 54 across 2019–2025, with 3.7% of August days above AQI 100. Ground-level ozone is the main driver.
- ✓40.6% of August days were Good (AQI 0–50), 55.8% Moderate (51–100).
- ✓8 days of 217 reached AQI 101+; the August peak was 133.
- ✓Best August: 2025; worst August: 2019.
Frequently asked questions
What is the air quality like in Washington in August?▾
Across 2019–2025, the median daily AQI in Washington in August was 54 (Moderate). 40.6% of days were Good, 55.8% Moderate, and 3.7% reached Unhealthy for Sensitive Groups or worse, based on 217 monitored days in EPA's Air Quality System.
Is August a good time for outdoor exercise in Washington?▾
A typical August day in Washington 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 27 of August days (3.7%) reached AQI 101+ — the level at which EPA advises people with asthma, children and older adults to shorten hard outdoor exertion.
Which pollutant causes Washington's August air quality problems?▾
Ground-level ozone set the daily AQI on 59.0% of August days in Washington. The highest August AQI recorded in 2019–2025 was 133 (Unhealthy for Sensitive Groups), in 2019.
Washington August air quality, year by year
Washington August air quality by year (Washington-Arlington-Alexandria, DC-VA-MD-WV, EPA AQS daily AQI)
| Year | Days monitored | Median AQI | Days above 100 | Peak AQI | Main pollutant |
|---|---|---|---|---|---|
| 2019worst | 31 | 59 | 3 | 122 | O3 |
| 2020 | 31 | 51 | 0 | 71 | PM2.5 |
| 2021 | 31 | 61 | 2 | 129 | O3 |
| 2022 | 31 | 50 | 0 | 77 | O3 |
| 2023 | 31 | 54 | 0 | 100 | O3 |
| 2024 | 31 | 56 | 3 | 133 | O3 |
| 2025cleanest | 31 | 46 | 0 | 93 | O3 |
What August air means in Washington
A typical August day in Washington 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 27 of August days (3.7%) reached AQI 101+ — the level at which EPA advises people with asthma, children and older adults to shorten hard outdoor exertion.
August's median AQI of 54 is in line with Washington's whole-year median of 52, so this period is neither a clean nor a dirty stretch for the area. Nationally, the median August AQI across every EPA metro area (104,152 metro-days, 2019–2025) is 45, so Washington runs above the national August norm; 3.7% of its August days topped AQI 100 versus 3.5% nationally (about the same).
August is part of Washington's summer season (June, July, August); the summer page pools all three months.
Activity-specific thresholds: running, cycling, kids' sports.
Right now in Washington
The latest EPA AirNow observation puts Washington's AQI at 41 (PM2.5). The figures above are multi-year month statistics, not today's reading.
View current Washington air quality →Source: EPA Air Quality System (AQS) pre-generated Daily AQI by CBSA files — daily AQI by CBSA (Washington-Arlington-Alexandria, DC-VA-MD-WV), 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.