Portland, ME Climate in May

Temperature for May

In Portland, ME during May the average high temperature is 65.5°F. The hottest day on record was May 31, 1987 when the temperature hit 93.0°F.

Portland, ME daily average and extreme temperature range for May

Low Temperature

During May the overnight temperature drops to an average of 43.4°F, with the lowest temperature of 25.9°F being recorded on May 1, 1978. Overnight temperatures drop below freezing between 1 and 7 times in May.

Precipitation for May

In May the average monthly rainfall in Portland, ME is 4.46 inches with rain usually falling on between 14 and 15 days. 1975 was the driest May with only 0.58 inches of rain falling, and 1973 was the wettest May with 25.05 inches of rain. The wettest single day in May was 25 May 1973 when 5.98 inches of rain fell.

In May it usually snows on between 0 and 1 days. There are thunderstorms on between 1 and 2 days in May.