Longmont Colorado Climate Data

Monthly Average Climate Data for Longmont Colorado

Switch Data to Celsius/Metric Units
MonthAvg. LowAvg. HighAvg. Precip
January15.3 °F44.1 °F0.39 in.
February17.8 °F46.0 °F0.52 in.
March26.0 °F56.3 °F1.31 in.
April32.9 °F63.0 °F1.86 in.
May42.6 °F71.7 °F2.78 in.
June51.5 °F84.0 °F1.53 in.
July57.5 °F90.1 °F1.25 in.
August55.0 °F87.7 °F1.82 in.
September46.4 °F79.8 °F1.4 in.
October34.4 °F66.1 °F1.11 in.
November24.0 °F53.2 °F0.79 in.
December15.4 °F43.7 °F0.49 in.
Annual34.9 °F65.5 °F15.25 in.

Climate Data for Longmont 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 ConditionsAbnormally Dry
Köppen Climate ClassificationDfa - Humid Continental Hot Summers With Year Around Precipitation
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