SmokeDarDuluth wildfire smoke and air quality
Live readings for Duluth, Minnesota: whether wildfire smoke is overhead, what the surface air measures, and how the next five days look. Free, no signup, no ads.
How smoke reaches Duluth
Duluth sits closest of all SmokeDar cities to the boreal fire belt, with the Boundary Waters and Ontario fire country immediately upwind. Lake Superior's cold surface air can trap smoke in a shallow layer along the shore, producing some of the region's thickest readings. That is why SmokeDar reports two numbers for Duluth: smoke aloft (modeled aerosol optical depth from Copernicus CAMS) and surface air (PM2.5 and US AQI, observed AirNow monitor data when a monitor is nearby). They are different things, and they often disagree.
What the numbers mean
AQI 0–50 is good and 51–100 is moderate; ordinary days. From 101–150, sensitive groups (kids, older adults, pregnant people, anyone with heart or lung conditions) should shorten hard outdoor exercise. Above 150, everyone should cut both time and intensity outdoors. The full playbook is in the Smoke Guide.