Boulder Colorado Climate Data

Monthly Average Climate Data for Boulder Colorado

Switch Data to Fahrenheit
MonthAvg. LowAvg. HighAvg. Precip
January-6.9 °C7.7 °C15.24 mm
February-6.2 °C8.2 °C20.07 mm
March-2.1 °C13.2 °C44.45 mm
April1.3 °C16.4 °C66.8 mm
May6.3 °C21.2 °C77.72 mm
June11.3 °C28 °C46.23 mm
July14.7 °C31.4 °C45.72 mm
August13.6 °C30.3 °C36.07 mm
September9.2 °C25.9 °C50.8 mm
October2.6 °C18.7 °C37.34 mm
November-2.8 °C12.1 °C23.11 mm
December-6.9 °C7.3 °C16.51 mm
Annual2.8 °C18.4 °C480.06 mm

Climate Data for Boulder Colorado

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 : -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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