Portland weather by month
What a typical year looks like in Portland, Maine: average highs and lows, rain and snow, and the warmest and coldest days on record. Normals are the 1991–2020 averages at Portland Jetport, 10 km from Portland; records cover 1874–2026.
The year at a glance
- Precipitation a year
- 48.1 in1222 mm
- Snow a year
- 69 in174 cm
- Last spring freeze
- Apr 30
- First fall freeze
- Oct 9
- Heating degree days
- 6,794
- Cooling degree days
- 446
Freeze dates are medians (half of years earlier, half later). Degree days use a 65°F base; HVAC design temperatures here are −3°−19° (heating, 99%) and 91°33° (cooling, 1%).
Month by month
Portland in January
Highs average 32°0° and lows 16°−9°, with 3.5 in89 mm of precipitation and 19 in47 cm of snow in a typical January.
- Record high
- 67°19° (2007)
- Record low
- −26°−32° (1971)
- Heating degree days
- 1271
- Cooling degree days
- 0
Portland in February
Highs average 35°2° and lows 17°−8°, with 3.5 in90 mm of precipitation and 17 in42 cm of snow in a typical February.
- Record high
- 68°20° (2018)
- Record low
- −39° (1943)
- Heating degree days
- 1088
- Cooling degree days
- 0
Portland in March
Highs average 42°6° and lows 26°−3°, with 4.1 in104 mm of precipitation and 14 in35 cm of snow in a typical March.
- Record high
- 88°31° (1998)
- Record low
- −21°−29° (1950)
- Heating degree days
- 956
- Cooling degree days
- 0
Portland in April
Highs average 54°12° and lows 35°2°, with 4.4 in112 mm of precipitation and 2.8 in7.1 cm of snow in a typical April.
- Record high
- 92°33° (2009)
- Record low
- 8°−13° (1954)
- Heating degree days
- 613
- Cooling degree days
- 1
Portland in May
Highs average 64°18° and lows 46°8°, with 3.7 in93 mm of precipitation in a typical May.
- Record high
- 96°36° (1937)
- Record low
- 23°−5° (1956)
- Heating degree days
- 325
- Cooling degree days
- 10
Portland in June
Highs average 74°23° and lows 55°13°, with 4.2 in105 mm of precipitation in a typical June.
- Record high
- 99°37° (2025)
- Record low
- 33°1° (1944)
- Heating degree days
- 89
- Cooling degree days
- 68
Portland in July
Highs average 80°26° and lows 61°16°, with 3.4 in87 mm of precipitation in a typical July.
- Record high
- 103°39° (1911)
- Record low
- 40°4° (1962)
- Heating degree days
- 10
- Cooling degree days
- 176
Portland in August
Highs average 79°26° and lows 60°15°, with 3.6 in91 mm of precipitation in a typical August.
- Record high
- 103°39° (1975)
- Record low
- 33°1° (1965)
- Heating degree days
- 16
- Cooling degree days
- 146
Portland in September
Highs average 71°22° and lows 52°11°, with 3.8 in96 mm of precipitation in a typical September.
- Record high
- 96°36° (1929)
- Record low
- 23°−5° (1941)
- Heating degree days
- 145
- Cooling degree days
- 43
Portland in OctoberThis month
Highs average 60°15° and lows 41°5°, with 5.3 in133 mm of precipitation and 0.2 in0.5 cm of snow in a typical October.
- Record high
- 88°31° (1963)
- Record low
- 15°−9° (1976)
- Heating degree days
- 459
- Cooling degree days
- 2
Portland in November
Highs average 48°9° and lows 32°0°, with 4.3 in108 mm of precipitation and 2.3 in5.8 cm of snow in a typical November.
- Record high
- 79°26° (2024)
- Record low
- −6°−21° (1875)
- Heating degree days
- 748
- Cooling degree days
- 0
Portland in December
Highs average 38°3° and lows 22°−5°, with 4.5 in114 mm of precipitation and 15 in37 cm of snow in a typical December.
- Record high
- 71°22° (1998)
- Record low
- −21°−29° (1917)
- Heating degree days
- 1074
- Cooling degree days
- 0