Maine Air Quality & Wildfire Smoke
Live AQI for 1 Maine city, plus statewide air-quality alerts. Data from AirNow (U.S. EPA).
Wildfire smoke in Maine
Smoke risk across Maine concentrates in June through early August, driven by long-range transport from Quebec and Ontario, which arrives as a regional haze rather than a local plume.
We currently track one city in Maine. Its reading is for that monitoring area only and should not be read as a statewide figure.
Each city page below shows AirNow's reported AQI on the 2024 EPA breakpoints, with the reporting monitor and the observation time — see how we calculate AQI. Statewide watches and warnings come from the National Weather Service and appear at the top of this page when active.
The 68,408 people we track in Maine are all in the Portland area, so this page is effectively that metro's page with a wider lens. For the rest of Maine, the nearest tracked reading in a bordering state is usually the better proxy than a number from the opposite corner.
Cross-border check: the nearest city we track outside Maine is Boston, MA, about 98 miles southwest of Portland. Smoke does not stop at state lines — when a plume covers that city's monitors, Maine's edge nearest it is usually seeing the same air.
Our next-nearest tracked readings sit in Providence, RI (139 mi southwest) and Hartford, CT (178 mi southwest) — useful second opinions when Maine's own reading looks odd, and the honest picture of how coarse national smoke coverage is at this resolution.
About our Portland coverage
Portland is one of the Maine cities we track, with a population of about 68,408, in Cumberland County.
In a city this size local sources contribute relatively little to PM2.5, so the AQI here tends to track transported smoke closely — when the number climbs, it is usually because smoke has arrived rather than because local conditions changed. That makes the reading a comparatively clean signal, but it also means it can move fast.
Smoke risk here concentrates in June through early August, driven by long-range transport from Quebec and Ontario, which arrives as a regional haze rather than a local plume. Outside that window an elevated reading in Portland is more likely to be local — traffic, dust, or a temperature inversion holding everyday pollution near the ground — than wildfire smoke, and the dominant pollutant shown above is what tells the two apart.
For smoke preparation that applies anywhere — filtration, masks, a clean room — see our wildfire-smoke health guide and the clean-room setup.