South Portland Maine Climate Data

Monthly Average Climate Data for South Portland Maine

Switch Data to Celsius/Metric Units
MonthAvg. LowAvg. HighAvg. Precip
January16.5 °F32.2 °F3.51 in.
February18.3 °F34.6 °F3.51 in.
March26.4 °F41.2 °F4.04 in.
April36.7 °F52.4 °F4.26 in.
May46.5 °F62.7 °F3.62 in.
June56.1 °F72.4 °F4.25 in.
July61.6 °F77.7 °F3.39 in.
August61.5 °F77.6 °F3.32 in.
September54.0 °F70.6 °F4.06 in.
October43.1 °F59.0 °F4.62 in.
November33.4 °F48.1 °F4.18 in.
December23.8 °F38.3 °F4.52 in.
Annual39.8 °F55.6 °F47.28 in.

Climate Data for South Portland Maine

Average First Frost DateOct. 11 - Oct. 20
Average Last Frost DateMay 21 - May 31
Average Days With Frost125-150 Days
Plant Hardiness Zone - 2023Zone 6a : -10°F to -5°F
Plant Hardiness Zone - 2012Zone 5b : -15°F to -10°F
Current Drought ConditionsNormal
Köppen Climate ClassificationDfb - Humid Continental Mild Summer, Wet All Year