Johnstown Colorado Climate Data

Monthly Average Climate Data for Johnstown Colorado

Switch Data to Celsius/Metric Units
MonthAvg. LowAvg. HighAvg. Precip
January14.0 °F41.7 °F0.28 in.
February16.6 °F44.2 °F0.43 in.
March25.2 °F55.1 °F0.98 in.
April32.5 °F61.7 °F1.48 in.
May42.7 °F70.5 °F2.51 in.
June52.1 °F82.6 °F1.63 in.
July57.3 °F88.6 °F1.66 in.
August54.9 °F86.4 °F1.29 in.
September46.1 °F78.8 °F1.33 in.
October33.9 °F64.9 °F0.9 in.
November22.9 °F51.7 °F0.56 in.
December14.1 °F41.5 °F0.53 in.
Annual34.4 °F64 °F13.58 in.

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 : -15°F to -10°F
Plant Hardiness Zone - 2012Zone 5b : -15°F to -10°F
Current Drought ConditionsNormal
Köppen Climate ClassificationBSk - Cold Semi-Arid Climate