Chelmsford Massachusetts Climate Data

Monthly Average Climate Data for Chelmsford Massachusetts

Switch Data to Fahrenheit
MonthAvg. LowAvg. HighAvg. Precip
January-9.4 °C1.5 °C92.96 mm
February-8.3 °C3.1 °C84.33 mm
March-4.1 °C7.3 °C110.49 mm
April1.7 °C14.3 °C100.84 mm
May7.4 °C20.3 °C96.52 mm
June12.7 °C25.2 °C107.7 mm
July15.9 °C28.4 °C95.76 mm
August15 °C27.6 °C97.03 mm
September10.6 °C23.7 °C98.04 mm
October4.1 °C16.8 °C123.95 mm
November-1.1 °C10.5 °C98.55 mm
December-5.7 °C4.7 °C113.54 mm
Annual3.2 °C15.3 °C1219.71 mm

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 : -23.3°C to -20.6°C
Plant Hardiness Zone - 2012Zone 6a : -23.3°C to -20.6°C
Current Drought ConditionsNormal
Köppen Climate ClassificationDfb - Humid Continental Mild Summer, Wet All Year
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