Indianapolis wildfire smoke and air quality

How smoke reaches Indianapolis

Indianapolis receives Canadian smoke after a long mid-continent journey, typically as a diffuse layer aloft. With no mountains or lakes to concentrate it, the usual signature is a washed-out sky and moderate AQI, with genuine Unhealthy days arriving only in the biggest fire seasons. That is why SmokeDar reports two numbers for Indianapolis: 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.