Portland Temperatures: Averages by Month
The numbers here tell you how hot and cold the weather usually is in Portland, Maine during each month of the year.
The average high and low temperatures are listed below monthly and annually for the city, in both degrees Fahrenheit and Celsius.
Maximums and minimums are only part of the temperature picture. To fill in the rest, there's information on how many days a month get above or below a given temperature.
To find out how often it rises over 70, 80 or 90 °F each month in Portland, scroll down farther. There are also monthly and yearly counts of days with cold weather.
All the numbers are long-term historical averages based on climate data gathered from 1981 to 2010.
|High °F||Low °F||High °C||Low °C|
Days of Hot Weather in Portland
Portland doesn't often get really hot, averaging just four days a year with temperatures in the 90s Fahrenheit. And it's not expected to reach 100 °F (38 °C) here. But that 90-degree weather can appear anytime from May to September, although it's most likely to occur in July.
How Often Portland Has Cold Temperatures
Portland typically has 142 frosty nights a year. Most nights from December to March are below 32 °F and normally seven of those drop to 0 °F (-18 °C) or less.
For an average of 40 days annually the thermometer never rises above freezing. Days that chilly can occur from November to April, including half the days in January.
National Climatic Data Center. NOAA's 1981-2010 Climate Normals.