Air Quality

+2 Days

Unhealthy air days in Maine remain low compared to past decades

No significant movement since the last available data

Benchmark: The overall number of days classified as a health risk and the severity of risks will be maintained through 2030.

Overview Fig. A


The State of Maine’s air quality index is based on ozone levels in parts per billion and tracks the number of days each year when the maximum ozone level recorded in Maine reaches moderate or unhealthy levels. Maine’s air quality contributes to health and wellness, and makes it an attractive place to live, do business, and visit. Air quality is subject to factors both within and beyond our borders.

In 2020, there were 25 moderate air quality days, and 1 day rated unhealthy for sensitive groups. After declining in the 1980s and 1990s, air quality in Maine has improved substantially, and is better than other Northeastern states.

Fig. A

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Maine Air Quality Index

Maine Department of Environmental Protection