The Maine Department of Environmental Protection has issued an air quality alert for the state that will be in effect throughout Monday afternoon and into Tuesday.
The notice for most of Maine means that people with heart or lung diseases, as well as asthma, should avoid strenuous activity.
Officials recommend closing windows and circulating indoor air with a fan or air conditioner, as well as avoiding prolonged strenuous activity.
Smoke from wildfires that are happening on the West Coast and in central and western Canada has been carried on winds across the country, and is causing particle pollution throughout New England, officials said.
By Tuesday afternoon, northern and central Maine should see some air quality improvement. Coastal and western areas will continue to see heightened levels of air pollution until Tuesday evening.