Washington Air Quality in March
Across 2019–2025, Washington's March air quality had a median AQI of 48 (Good) over 217 monitored days in the Washington-Arlington-Alexandria, DC-VA-MD-WV area. 0.0% of March days (0 of 217) reached Unhealthy for Sensitive Groups or worse, and ground-level ozone set the daily AQI on 52.5% of days. The cleanest March on record here was 2020 (median AQI 43, 0 days above 100) and the worst was 2022 (median 51, 0 days above 100, peak AQI 65).
- Good: 59.0%
- Moderate: 41.0%
- Unhealthy for Sensitive Groups: 0.0%
- Unhealthy or worse: 0.0%
Improve Indoor Air Quality
Even with good outdoor air in Washington, indoor PM2.5, dust and allergens build up. A True-HEPA purifier keeps a bedroom or office consistently clean.
Recommended: Levoit Core 400S — True HEPA · CADR ~141 CFM · rooms up to 219 sq ft
As an Amazon Associate, we earn from qualifying purchases.
How is the air in Washington in March?
Good on a typical day: median AQI 48 across 2019–2025, with 0.0% of March days above AQI 100. Ground-level ozone is the main driver.
- ✓59.0% of March days were Good (AQI 0–50), 41.0% Moderate (51–100).
- ✓0 days of 217 reached AQI 101+; the March peak was 77.
- ✓Best March: 2020; worst March: 2022.
Frequently asked questions
What is the air quality like in Washington in March?▾
Across 2019–2025, the median daily AQI in Washington in March was 48 (Good). 59.0% of days were Good, 41.0% Moderate, and 0.0% reached Unhealthy for Sensitive Groups or worse, based on 217 monitored days in EPA's Air Quality System.
Is March a good time for outdoor exercise in Washington?▾
A typical March 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; fewer than 1% of March days reached AQI 101+ in 2019–2025.
Which pollutant causes Washington's March air quality problems?▾
Ground-level ozone set the daily AQI on 52.5% of March days in Washington. The highest March AQI recorded in 2019–2025 was 77 (Moderate), in 2022.
Washington March air quality, year by year
Washington March 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 | 31 | 51 | 0 | 77 | PM2.5 |
| 2020cleanest | 31 | 43 | 0 | 61 | PM2.5 |
| 2021 | 31 | 48 | 0 | 77 | PM2.5 |
| 2022worst | 31 | 51 | 0 | 65 | PM2.5 |
| 2023 | 31 | 48 | 0 | 72 | O3 |
| 2024 | 31 | 43 | 0 | 77 | O3 |
| 2025 | 31 | 45 | 0 | 66 | O3 |
What March air means in Washington
A typical March 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; fewer than 1% of March days reached AQI 101+ in 2019–2025.
March'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 March AQI across every EPA metro area (102,455 metro-days, 2019–2025) is 42, so Washington runs above the national March norm; 0.0% of its March days topped AQI 100 versus 0.4% nationally (about the same).
March is part of Washington's spring season (March, April, May); the spring 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.