Boston vs Washington Air Quality Comparison
Which city has cleaner air right now, from the latest EPA AirNow AQI
As of November 14, 2026, Boston, MA has cleaner air than Washington, DC — AQI 25 (Good) vs 29 (Good), a gap of 4 AQI points in the latest EPA AirNow observations. Lower AQI means cleaner air. Boston's reading is driven by PM2.5 and Washington's by O3.
Boston, MA
Good
Washington, DC
Good
Summary
Boston has 4 points better air quality
Boston has an AQI of 25 compared to 29
Reduce Indoor Ozone in Washington
Today's main pollutant in Washington is ground-level ozone (AQI 29). Important: standard HEPA filters do NOT remove ozone — only a purifier with a substantial activated-carbon bed adsorbs it. The biggest wins are cutting indoor sources (gas appliances, certain "ionizer" purifiers) and ventilating when outdoor ozone is low (early morning). A high-carbon unit helps with the gases and VOCs that linger indoors.
Compare activated-carbon purifiers (for gases & ozone):
Prices are approximate and subject to change. As an Amazon Associate, we earn from qualifying purchases at no extra cost to you.
5-Day Forecast Comparison
| Day | Boston | Washington | Better |
|---|---|---|---|
| Today | AQI 30 | AQI 22 | Washington |
| Sat, Nov 14 | AQI 30 | AQI 22 | Washington |
| Sun, Nov 15 | AQI 35 | AQI 28 | Washington |
| Mon, Nov 16 | AQI 45 | AQI 33 | Washington |