DEP Issues Air Quality Alert for Northern Maine on July 15

July 15, 2025

Update:

Ground-level particle pollution concentrations are expected to reach the 'Unhealthy for Sensitive Groups' (USG) level according to the Maine Department of Environmental Protection.

This morning, a dense portion of the smoke plume moved into northern Maine. This plume is expected to linger in the Northern region into Wednesday, with less dense smoke impacting the remainder of the state. Thus, Particle Pollution levels are expected to be in the USG range for the Northern region and Moderate for the remainder of the state. Also on Wednesday, Ozone is expected to be Moderate for the entire coast, Good for inland regions and USG for the High Elevations of Acadia National Park.

By Thursday, the densest portion of the smoke plume should finally move out of Maine, though Moderate levels of Particle Pollution are still likely for most of the state. We cant rule out some hours of Ozone buildup, but storms have the potential to keep ozone levels in the Good range. Thursdays forecast will be updated Wednesday afternoon.

Ground-level particle pollution concentrations are expected to reach the 'Unhealthy for Sensitive Groups (USG)' level according to the Maine Department of Environmental Protection.

This morning, USG levels of particle pollution are being reported in the Northern region of Maine due to wildfire smoke. Particle pollution values averaged in the USG range just west of Maine in Quebec yesterday. Hourly values in Quebec continue to be in the USG range this morning. Smoke is expected to continue moving into Maine from Quebec as westerly winds become prevalent this afternoon. The remainder of the state is expected to reach the Moderate range.

Currently, the dense portion of the plume should move out on Wednesday, but the smoke is not projected to leave Maine until Thursday. The entire state of Maine is expected to remain in the Moderate range for particle pollution on Wednesday and Thursday. Air quality meteorologists will monitor the situation and update Wednesdays forecast this afternoon.

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