Johnstown Colorado Climate Data

Monthly Average Climate Data for Johnstown Colorado

Switch Data to Fahrenheit
MonthAvg. LowAvg. HighAvg. Precip
January-10 °C5.4 °C7.11 mm
February-8.6 °C6.8 °C10.92 mm
March-3.8 °C12.8 °C24.89 mm
April0.3 °C16.5 °C37.59 mm
May5.9 °C21.4 °C63.75 mm
June11.2 °C28.1 °C41.4 mm
July14.1 °C31.4 °C42.16 mm
August12.7 °C30.2 °C32.77 mm
September7.8 °C26 °C33.78 mm
October1.1 °C18.3 °C22.86 mm
November-5.1 °C10.9 °C14.22 mm
December-9.9 °C5.3 °C13.46 mm
Annual1.3 °C17.8 °C344.91 mm

Climate Data for Johnstown Colorado

Average First Frost DateOct. 1 - Oct. 10
Average Last Frost DateMay 21 - May 31
Average Days With Frost150-180 Days
Plant Hardiness Zone - 2023Zone 5b : -26.1°C to -23.3°C
Plant Hardiness Zone - 2012Zone 5b : -26.1°C to -23.3°C
Current Drought ConditionsNormal
Köppen Climate ClassificationBSk - Cold Semi-Arid Climate