Chelmsford Massachusetts Climate Data

Monthly Average Climate Data for Chelmsford Massachusetts

Switch Data to Celsius/Metric Units
MonthAvg. LowAvg. HighAvg. Precip
January15.1 °F34.7 °F3.66 in.
February17.0 °F37.5 °F3.32 in.
March24.6 °F45.2 °F4.35 in.
April35.1 °F57.8 °F3.97 in.
May45.4 °F68.5 °F3.8 in.
June54.8 °F77.3 °F4.24 in.
July60.6 °F83.2 °F3.77 in.
August59.0 °F81.7 °F3.82 in.
September51.0 °F74.6 °F3.86 in.
October39.3 °F62.3 °F4.88 in.
November30.0 °F50.9 °F3.88 in.
December21.7 °F40.4 °F4.47 in.
Annual37.8 °F59.5 °F48.02 in.

Climate Data for Chelmsford Massachusetts

Average First Frost DateOct. 1 - Oct. 10
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 6a : -10°F to -5°F
Current Drought ConditionsNormal
Köppen Climate ClassificationDfb - Humid Continental Mild Summer, Wet All Year