Harlan Iowa Climate Data

Monthly Average Climate Data for Harlan Iowa

Switch Data to Celsius/Metric Units
MonthAvg. LowAvg. HighAvg. Precip
January11.1 °F29.8 °F0.87 in.
February15.3 °F34.6 °F1.07 in.
March26.2 °F48.1 °F1.95 in.
April37.1 °F61.1 °F3.59 in.
May49.6 °F71.6 °F4.84 in.
June60.0 °F81.2 °F4.97 in.
July63.8 °F84.4 °F3.74 in.
August60.9 °F82.5 °F4.24 in.
September51.7 °F76.6 °F3.63 in.
October39.8 °F64.1 °F2.66 in.
November27.0 °F47.6 °F1.44 in.
December17.0 °F34.8 °F1.29 in.
Annual38.3 °F59.7 °F34.29 in.

Climate Data for Harlan Iowa

Average First Frost DateOct. 1 - Oct. 10
Average Last Frost DateMay 11 - May 20
Average Days With Frost150-180 Days
Plant Hardiness Zone - 2023Zone 5b : -15°F to -10°F
Plant Hardiness Zone - 2012Zone 5a : -20°F to -15°F
Current Drought ConditionsModerate Drought
Köppen Climate ClassificationDfa - Humid Continental Hot Summers With Year Around Precipitation
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