Hazy sunlight is a sign that smoke from wildfires elsewhere has reached Maine, but the worst of it is expected to clear out by Tuesday evening.

Maine’s Department of Environmental Protection says a Canadian wildfire is the main driver of hazy skies, as well as ongoing fires in the western U.S.

The department forecasted unhealthy particle pollution conditions for sensitive groups both Monday and Tuesday. It says Mainers with heart or lung disease, the elderly, teenagers and children should reduce prolonged or heavy exertion.

The highest levels of smoke were expected from midday Monday through Tuesday afternoon or evening.