Washington, DC Air Quality Index (AQI) Today
DCDominant: O3 LIVERight now: Washington is at 42, good.
Is the air safe to breathe in Washington today?
In Washington, BreatheCheck reads 42 as Go. The cutoffs: go below 101, keep it short and easy from 101 to 150, move it indoors above 150. These are our own thresholds, drawn on the EPA bands — EPA itself classifies 101–150 as Unhealthy for Sensitive Groups and does not tell you how long to stay out.
Go AQI 0–100
Normal outdoor plans. No change needed.
Short & unloaded AQI 101–150
A 20-minute dog walk, not a 2.5-hour run. Keep it brief and easy.
Don’t go AQI 151+
Move it indoors. Above 200 that becomes everyone, not just sensitive groups.
Above 200 this stops being a personal call: everyone indoors.
Duration and intensity are two separate dials
| Under 20 min | 20–60 min | Over an hour | |
|---|---|---|---|
| Easy | Go | Go | Go |
| Moderate | Go | Go | Go |
| Hard | Go | Go | Go |
Go Every combination lands the same way at this reading — a hard hour is no different from an easy twenty minutes. The two dials separate above 80.
Where people actually draw the line
All the thresholds people reported, and who reported them
- 60 Asthmatic runnerone runner’s own 156-run log
- 75–100 Daycare / schoolparents and staff in one r/toddlers thread, Aug 2025 — not a published rule
- 100 Parentcommunity-reported, escalating at 150 and 200
- 110 Runnercommunity-reported
If you’re staying in, filter the room you’re actually in
A Fall Line corridor that imports its worst air
Washington occupies the Fall Line, where the Piedmont steps down to the Atlantic Coastal Plain at the junction of the Potomac and the Anacostia, and most of the District lies close to sea level. Air moves through the place rather than settling into it, which is why the worst days here are usually made somewhere else and delivered.
In summer that means ozone. Under a stalled high the flow turns hot and southwesterly, and emissions from the length of the I-95 corridor and from farther inland keep reacting while they travel. Research on the Chesapeake has documented a second mechanism: a bay breeze developing along the western shore converges pollutants near its front and lifts ozone on the days it forms. Washington sits inland of where that effect is strongest, but shares the airshed it feeds.
The other import is smoke. On June 8, 2023, plumes from fires in Quebec pushed the region past Code Red into a rare Code Purple, and Major League Baseball postponed the Nationals game scheduled in the city that night. Nothing that produced that day was burning anywhere in the mid-Atlantic.
The District itself has almost no heavy industry to contribute. What it adds between those events is vehicles, concentrated on the Beltway and the radial corridors that feed into it.
Where this number sits
Of the 121 US metros reporting to us right now, Washington is number 57. The pollutant driving it today is O3.
Nearby metros we also measure, and what they read at the same hour:
- Baltimore, MD — 35 miles away, AQI 37
- Frederick, MD — 40 miles away, AQI 33
- Dover, DE — 84 miles away, AQI 37
- Richmond, VA — 96 miles away, AQI 39
Where this reading comes from
AirNow’s Northern Virginia and DC reporting area, about 2 miles from the metro centre.
What has air quality in Washington actually been?
1 of the 30 days we have recorded so far went above AQI 100.
| Date | Daily max AQI | EPA band | Hours read |
|---|---|---|---|
| 43 | Good | 22 | |
| 47 | Good | 23 | |
| 58 | Moderate | 23 | |
| 54 | Moderate | 23 | |
| 60 | Moderate | 23 | |
| 56 | Moderate | 22 | |
| 56 | Moderate | 23 | |
| 55 | Moderate | 23 | |
| 55 | Moderate | 23 | |
| 52 | Moderate | 23 | |
| 72 | Moderate | 23 | |
| 77 | Moderate | 24 | |
| 65 | Moderate | 23 | |
| 68 | Moderate | 23 | |
| 74 | Moderate | 23 | |
| 58 | Moderate | 23 | |
| 61 | Moderate | 23 | |
| 107 | Unhealthy for Sensitive Groups | 22 | |
| 84 | Moderate | 23 | |
| 59 | Moderate | 23 | |
| 57 | Moderate | 23 | |
| 56 | Moderate | 24 | |
| 57 | Moderate | 23 | |
| 74 | Moderate | 23 | |
| 84 | Moderate | 23 | |
| 71 | Moderate | 23 | |
| 67 | Moderate | 23 | |
| 58 | Moderate | 23 | |
| 71 | Moderate | 26 | |
| 56 | Moderate | 6 — partial day |
Questions about Washington
What is the air quality in Washington right now?
Which monitor does this number come from?
How does Washington compare with metros nearby?
Does this include pollen?
Put this number in context
Updated