Washington Air Quality in 2023
In 2023, Washington's air quality (Washington-Arlington-Alexandria, DC-VA-MD-WV area) had a median daily AQI of 52 (Moderate) across 365 monitored days. 20 days (5.5%) reached Unhealthy for Sensitive Groups or worse, 158 were Good, and the year's peak AQI was 222 (Very Unhealthy). Fine particulate matter (PM2.5) set the daily AQI on 198 of those days. The cleanest month of 2023 was January (median AQI 46, 0 days above 100) and the worst was June (median 79, 10 days above 100, peak 222).
- Good: 43.3%
- Moderate: 51.2%
- Unhealthy for Sensitive Groups: 4.4%
- Unhealthy or worse: 1.1%
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How was Washington's air quality in 2023?
Moderate on a typical day: median AQI 52, with 20 days above AQI 100 out of 365 monitored — the 7th cleanest of 7 years on record for the area.
- ✓Peak AQI in 2023: 222 (Very Unhealthy).
- ✓Fine particulate matter (PM2.5) was the main pollutant on 198 days.
- ✓Cleanest month: January; worst: June.
Frequently asked questions
What was the average AQI in Washington in 2023?▾
EPA's Air Quality System puts Washington's (Washington-Arlington-Alexandria, DC-VA-MD-WV) median daily AQI for 2023 at 52, which is Moderate. 20 days were Unhealthy for Sensitive Groups or worse and the year's highest AQI was 222.
Which month had the worst air quality in Washington in 2023?▾
The cleanest month of 2023 was January (median AQI 46, 0 days above 100) and the worst was June (median 79, 10 days above 100, peak 222).
Was 2023 a good or bad year for Washington's air?▾
Among the 7 years EPA has published for the area (2019–2025), 2023 ranks 7th cleanest by days above AQI 100 — the worst year on record here. 2023's median of 52 is in line with the area's typical annual median of 52.
Washington month by month in 2023
Washington air quality month by month, 2023 (Washington-Arlington-Alexandria, DC-VA-MD-WV, EPA AQS daily AQI)
| Month | Days monitored | Median AQI | Days above 100 | Peak AQI | Main pollutant |
|---|---|---|---|---|---|
| Januarycleanest | 31 | 46 | 0 | 71 | PM2.5 |
| February | 28 | 47 | 0 | 64 | PM2.5 |
| March | 31 | 48 | 0 | 72 | O3 |
| April | 30 | 53 | 2 | 115 | O3 |
| May | 31 | 54 | 1 | 119 | O3 |
| Juneworst | 30 | 79 | 10 | 222 | O3 |
| July | 31 | 64 | 7 | 131 | O3 |
| August | 31 | 54 | 0 | 100 | O3 |
| September | 30 | 48 | 0 | 84 | O3 |
| October | 31 | 47 | 0 | 84 | PM2.5 |
| November | 30 | 50 | 0 | 68 | PM2.5 |
| December | 31 | 51 | 0 | 74 | PM2.5 |
How 2023 compares
Among the 7 years EPA has published for the area (2019–2025), 2023 ranks 7th cleanest by days above AQI 100 — the worst year on record here.
2023's median of 52 is in line with the area's typical annual median of 52.
Activity-specific thresholds: running, cycling, kids' sports.
Right now in Washington
The latest EPA AirNow observation puts Washington's AQI at 43 (PM2.5). The figures above are multi-year annual 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.