05/01/2026 | Press release | Archived content
Maine is proud to have some of the best air quality in the nation; however, ground-level ozone and small particles can still pose significant health risks, especially during warmer months. Ozone is formed when sunlight and heat catalyze chemical reactions with pollutants from various sources, while particulate pollution results from both natural and man-made processes, including dust, soil, soot, smoke, and sea salt.
In recent years, Maine has seen an increase in smoke from wildfires in the western United States and Canada. Reducing exposure is important for everyone's health - especially children, older adults, and people with heart or lung disease. When wildfires create smoky conditions, there are things you can do, indoors and out, to reduce your exposure to smoke:
Maine DEP forecasts ozone and particle pollution year-round. Forecasts are available on DEP's website, via toll free hotline, EnviroFlash emails and text messages.
Using the Environmental Protection Agency's color-coded Air Quality Index (AQI), the DEP categorizes air quality into six levels: Green for good, Yellow for moderate, Orange indicating unhealthy pollution levels for sensitive groups, Red for unhealthy levels for everyone, Purple for very unhealthy, and Maroon for hazardous conditions.
While those with respiratory or heart conditions and other sensitive groups may experience effects at lower pollution levels, everyone is encouraged to take steps to minimize exposure when air quality reaches Unhealthy for Sensitive Groups (USG) or higher.
Reducing air pollution is a shared responsibility. The DEP urges all residents to consider their impact and adopt simple behaviors that contribute to cleaner air, especially on days when pollution levels are forecasted to be unhealthy.
Recommended actions include:
These small changes can collectively make a significant difference in protecting community health and the environment.
In recognition of Air Quality Awareness Week, the Maine DEP will highlight daily topics related to air quality on its Maine DEP's Air Quality Forecast website. These updates provide information to help residents stay informed and engaged in efforts to improve air quality across the state.
For more information and to receive air quality forecasts, visit the Maine DEP's Air Quality Forecast website or sign up for EnviroFlash alerts.