Harlan Iowa Climate Data

Monthly Average Climate Data for Harlan Iowa

Switch Data to Fahrenheit
MonthAvg. LowAvg. HighAvg. Precip
January-11.6 °C-1.2 °C22.1 mm
February-9.3 °C1.4 °C27.18 mm
March-3.2 °C8.9 °C49.53 mm
April2.8 °C16.2 °C91.19 mm
May9.8 °C22 °C122.94 mm
June15.6 °C27.3 °C126.24 mm
July17.7 °C29.1 °C95 mm
August16.1 °C28.1 °C107.7 mm
September10.9 °C24.8 °C92.2 mm
October4.3 °C17.8 °C67.56 mm
November-2.8 °C8.7 °C36.58 mm
December-8.3 °C1.6 °C32.77 mm
Annual3.5 °C15.4 °C870.99 mm

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 : -26.1°C to -23.3°C
Plant Hardiness Zone - 2012Zone 5a : -28.9°C to -26.1°C
Current Drought ConditionsModerate Drought
Köppen Climate ClassificationDfa - Humid Continental Hot Summers With Year Around Precipitation
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