Groton Massachusetts Climate Data

Monthly Average Climate Data for Groton Massachusetts

Switch Data to Celsius/Metric Units
MonthAvg. LowAvg. HighAvg. Precip
January15.0 °F34.1 °F3.55 in.
February16.6 °F36.9 °F3.36 in.
March24.7 °F44.7 °F4.27 in.
April35.5 °F58.1 °F3.97 in.
May46.3 °F69.3 °F3.76 in.
June55.9 °F78.0 °F4.52 in.
July61.4 °F83.6 °F3.69 in.
August59.5 °F82.0 °F3.93 in.
September51.5 °F74.7 °F4.04 in.
October39.7 °F62.1 °F4.79 in.
November30.2 °F50.4 °F3.86 in.
December21.5 °F39.7 °F4.47 in.
Annual38.2 °F59.5 °F48.21 in.

Climate Data for Groton Massachusetts

Average First Frost DateOct. 1 - Oct. 10
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
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