Southwest Harbor Maine Climate Data

Monthly Average Climate Data for Southwest Harbor Maine

Switch Data to Celsius/Metric Units
MonthAvg. LowAvg. HighAvg. Precip
January15.3 °F31.2 °F4.6 in.
February16.6 °F32.9 °F3.85 in.
March24.4 °F39.5 °F4.74 in.
April34.3 °F50.0 °F4.51 in.
May43.5 °F60.3 °F4.37 in.
June52.0 °F69.6 °F4.2 in.
July57.9 °F75.3 °F3.24 in.
August57.7 °F75.0 °F3.01 in.
September51.7 °F68.1 °F4.1 in.
October41.7 °F57.0 °F5.67 in.
November32.4 °F46.9 °F5.53 in.
December22.0 °F37.3 °F5.55 in.
Annual37.5 °F53.6 °F53.37 in.

Climate Data for Southwest Harbor Maine

Average First Frost DateOct. 11 - Oct. 20
Average Last Frost DateMay 11 - May 20
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 ConditionsAbnormally Dry
Köppen Climate ClassificationDfb - Humid Continental Mild Summer, Wet All Year
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