Maine enjoys a very ideal and healthy climate overall with its moderate temperatures and virtually smog-free atmosphere. Along the coasts, conditions are governed by the Atlantic Ocean, resulting in lower summer and higher winter temperatures than are typical of the interior areas.

Maine enjoys one of the most comfortable summer climates in the continental United States. Peak temperatures, normally occurring in July, average about 70ºF throughout the State. In the Southern Interior Division during a very warm summer, temperatures may reach 90ºF for as many as 25 days, and in the Coastal Division, two to seven days. Summer nights are usually cool and comfortable. Winters are generally cold, but prolonged cold spells are rare. Temperature variations are greater in the winter than in summer. Northern Interior weather stations may record as many as 40 to 60 days of sub-zero temperatures annually, while coastal stations report ten to 20 sub-zero days.

The Annual precipitation in Maine averages 40 inches in the Northern Division, about 42 inches in the Southern Division and 46 inches in the Coastal Division. Although Maine is rarely subjected to freeze storms, hurricanes, and tornadoes, ten to 20 thunderstorms occur annually in the Coastal Division and 15 to 30 elsewhere.

Heavy ground fog often appears in low-lying inland areas, but occur most frequently along the coast, 25 to 60 days annually. The southern portion of the State has 80 to 120 clear days annually when there is no fog or other precipitation, and northern regions somewhat less. The percentage of possible sunshine varies from 50 percent in Eastport to about 60 percent in Portland.

Average snowfall in Maine is 50 to 70 inches annually in the Coastal Division, 60 to 90 inches in the Southern Interior and 90 to 110 inches in the Northern Interior Division. The Coastal Division rarely has more than 15 to 20 days annually with one inch or more snowfall, although a "Northeaster" storm may occasionally drop ten or more inches of snow in a single day. The Northern Interior may have up to 30 days a year with a minimum of one inch. January is normally the snowiest month with an average of about 20 inches.

National Weather Service Forecast for Maine