Wildfire Smoke Causes Poor Air Quality in DC Area

On July 17, 2026, a cold front brought a dense plume of wildfire smoke from Canada to the Washington, D.C. area, resulting in air quality levels classified as very unhealthy (code purple) to hazardous (code maroon). According to monitoring site IQAir, D.C. had the third-worst air quality among major cities globally, following Detroit and Chicago. The Metropolitan Washington Council of Governments issued a code purple alert, advising residents to reduce exposure to the smoke. Reports indicated that visibility in the area dropped significantly, from 10 miles to 1.25 miles by 7 a.m. on Friday. PM2.5 air quality values reached as high as 373 AQI in Ashburn, Virginia, compared to a maximum of 273 AQI during a previous wildfire smoke event in June 2023. The EPA warns that exposure to wildfire smoke can trigger health issues, particularly for vulnerable populations. Residents are advised to limit outdoor activities and consider wearing masks. The smoke is expected to linger through Friday night before improving on Saturday.