# Duluth wildfire smoke and air quality

Live readings for Duluth, Minnesota from SmokeDar (https://smokedar.com/duluth): 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. This explains the color of the sky.
- **Surface air**: PM2.5 and US AQI, using observed AirNow monitor data when a monitor is nearby. This is what reaches your lungs.

They are different things, and they often disagree. An orange sky can sit over clean surface air,
and hazy-looking days can measure fine.

## Is the air in Duluth safe to breathe today?

Use the US AQI number, not the sky's color:

- **0-50 (Good) and 51-100 (Moderate)**: ordinary days for most people.
- **101-150 (Unhealthy for sensitive groups)**: kids, older adults, pregnant people, and anyone with heart or lung conditions should shorten hard outdoor exercise.
- **151+ (Unhealthy and above)**: everyone should cut both time and intensity outdoors.

The current live reading is on https://smokedar.com/duluth and the full playbook is at
https://smokedar.com/smoke-guide.html.

## About SmokeDar

SmokeDar is a free wildfire smoke and air quality radar covering 21 cities across the eight
Midwest states (Minnesota, Wisconsin, Michigan, Iowa, Illinois, Indiana, Ohio, Missouri).
Built by Ryan Thompson in Milwaukee. It is not a health barometer; readings are modeled or
monitor-observed as labeled. More: https://smokedar.com/llms.txt