Washington Air Quality in Spring
Across 2019–2025, Washington's spring (March–May) air quality had a median AQI of 48 (Good) over 644 monitored days in the Washington-Arlington-Alexandria, DC-VA-MD-WV area. 1.1% of spring days (7 of 644) reached Unhealthy for Sensitive Groups or worse, and ground-level ozone set the daily AQI on 62.3% of days. The cleanest spring on record here was 2020 (median AQI 45, 0 days above 100) and the worst was 2023 (median 52, 3 days above 100, peak AQI 119).
- Good: 56.4%
- Moderate: 42.5%
- Unhealthy for Sensitive Groups: 1.1%
- Unhealthy or worse: 0.0%
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How is the air in Washington in spring?
Good on a typical day: median AQI 48 across 2019–2025, with 1.1% of spring days above AQI 100. Ground-level ozone is the main driver.
- ✓56.4% of spring days were Good (AQI 0–50), 42.5% Moderate (51–100).
- ✓7 days of 644 reached AQI 101+; the spring peak was 140.
- ✓Cleanest month: March; worst month: May.
Frequently asked questions
What is the air quality like in Washington in spring?▾
Across 2019–2025, the median daily AQI in Washington in spring was 48 (Good). 56.4% of days were Good, 42.5% Moderate, and 1.1% reached Unhealthy for Sensitive Groups or worse, based on 644 monitored days in EPA's Air Quality System.
Is spring a good time for outdoor exercise in Washington?▾
A typical spring day in Washington sits in the Good range (median AQI 48), so running, cycling and children's outdoor play are fine for everyone on most days; about 1 day in 91 of spring days (1.1%) reached AQI 101+ in 2019–2025.
Which pollutant causes Washington's spring air quality problems?▾
Ground-level ozone set the daily AQI on 62.3% of spring days in Washington. The highest spring AQI recorded in 2019–2025 was 140 (Unhealthy for Sensitive Groups), in 2023.
Washington spring air quality, year by year
Washington spring 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 |
|---|---|---|---|---|---|
| 2019 | 92 | 52 | 0 | 87 | O3 |
| 2020cleanest | 92 | 45 | 0 | 62 | O3 |
| 2021 | 92 | 49 | 3 | 140 | O3 |
| 2022 | 92 | 50 | 0 | 87 | O3 |
| 2023worst | 92 | 52 | 3 | 119 | O3 |
| 2024 | 92 | 46 | 1 | 105 | O3 |
| 2025 | 92 | 46 | 0 | 93 | O3 |
What spring air means in Washington
A typical spring day in Washington sits in the Good range (median AQI 48), so running, cycling and children's outdoor play are fine for everyone on most days; about 1 day in 91 of spring days (1.1%) reached AQI 101+ in 2019–2025.
Spring's median AQI of 48 is below Washington's whole-year median of 52, making it one of the area's cleaner periods. Nationally, the median Spring AQI across every EPA metro area (307,196 metro-days, 2019–2025) is 43, so Washington runs above the national Spring norm; 1.1% of its Spring days topped AQI 100 versus 0.8% nationally (about the same).
Within the season, March is the cleanest month (median AQI 48, 0.0% of days above 100) and May the worst (median 49, 2.3% above 100).
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 season 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.