Portland Maine Climate Data

Monthly Average Climate Data for Portland Maine

Switch Data to Fahrenheit
MonthAvg. LowAvg. HighAvg. Precip
January-8.7 °C0 °C88.9 mm
February-7.6 °C1.4 °C89.15 mm
March-3.1 °C5.2 °C102.36 mm
April2.7 °C11.5 °C108.97 mm
May8.1 °C17.2 °C91.69 mm
June13.4 °C22.6 °C107.7 mm
July16.6 °C25.8 °C87.12 mm
August16.4 °C25.5 °C84.07 mm
September12.2 °C21.6 °C102.36 mm
October6.2 °C15 °C120.65 mm
November0.7 °C8.9 °C106.68 mm
December-4.6 °C3.4 °C115.57 mm
Annual4.4 °C13.2 °C1205.22 mm

Climate Data for 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 : -23.3°C to -20.6°C
Plant Hardiness Zone - 2012Zone 5b : -26.1°C to -23.3°C
Current Drought ConditionsNormal
Köppen Climate ClassificationDfb - Humid Continental Mild Summer, Wet All Year
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