Ozone Seasonal Trend

There is a difference in ozone values between regions by month. The northern sites do not record high levels of ozone very often however; they typically see their peaks early in the season before 'leaf out' (when the leaves open up on trees and other vegetation starts growing). Coastal sites tend to peak in July and August.

In the chart below we've selected a northern site and a coastal site to display the difference between the two by looking at the daily 10 year average then adding a moving 7 day average. Notice that early in the season the two sites record very similar levels of ozone but once the leaves are on the trees there are significant differences in the levels of ozone recorded at these two extremes of Maine. As autumn progresses the two regions again record similar levels of ozone.

Air Quality trends

Ozone Seasonal Trend