Impact of Canadian Wildfire Smoke on Air Quality Anticipated in Areas of Maine

August 3, 2025

Today ground-level particle pollution concentrations are expected to reach 'Unhealthy levels in the Northern region and Unhealthy for Sensitive Groups in the Western Mountains and Western Interior regions' according to the Maine Department of Environmental Protection.

A plume of smoke from wildfires in Canada moved into Maine on Saturday. On Sunday a dense portion of the plume is expected to reach the ground in the Northern region: including all of Piscataquis & Aroostook counties, the northern 1/3 of Somerset, the northern half of Penobscot County and the northern half of Washington County.

A moderately dense portion of the plume is expected to impact the western regions: including all of Oxford and Franklin counties and the southern 2/3 of Somerset County; inland portions of York, Cumberland, Sagadahoc, and Lincoln counties; and all of Androscoggin and Kennebec counties. Onshore winds develop during the day keeping the remainder of the state from rising above the Moderate range.

The plume is expected to begin to move south through Maine on Monday. Some pockets of moderately dense smoke are possible. It is not likely to clear out of Maine before late Tuesday. There may be a need to extend the alert or add some additional areas so please check the air quality forecast page for the latest updates.

At elevated levels of particle pollution, children, the elderly, and individuals suffering from respiratory or heart diseases such as asthma, bronchitis, or COPD can experience reduced lung function and irritation. In addition, healthy adults who exert themselves outdoors may also notice these health effects. Affected individuals may notice symptoms such as coughing, shortness of breath, throat irritation, and/or experience mild chest pain.

Some actions you can take to protect your health during such periods of include:

  • Avoiding strenuous outdoor activity

  • Closing windows and circulating indoor air with a fan or air conditioner

  • Asthmatics should keep their quick-relief medications and action plan handy

Additional health information may be found on the following websites:

In addition to those in a sensitive group, others who are responsible for the welfare of people impacted by poor air quality are urged to use one of the listed tools to follow the Air Quality Forecast:

For more information go to Maine DEPs air quality web site.

For additional information, contact: David R. Madore, Deputy Commissioner david.madore@maine.gov