Janesville Iowa Climate Data

Monthly Average Climate Data for Janesville Iowa

Switch Data to Celsius/Metric Units
MonthAvg. LowAvg. HighAvg. Precip
January8.9 °F26.1 °F1.02 in.
February13.2 °F30.5 °F1.12 in.
March24.6 °F43.8 °F1.97 in.
April36.5 °F58.5 °F3.95 in.
May49.0 °F70.4 °F4.9 in.
June59.8 °F80.2 °F5.78 in.
July62.9 °F83.1 °F4.53 in.
August60.0 °F81.1 °F4.11 in.
September51.2 °F75.2 °F3.5 in.
October38.8 °F61.7 °F2.84 in.
November26.5 °F45.4 °F1.89 in.
December15.9 °F32.0 °F1.54 in.
Annual37.3 °F57.3 °F37.15 in.

Climate Data for Janesville Iowa

Average First Frost DateOct. 1 - Oct. 10
Average Last Frost DateMay 21 - May 31
Average Days With Frost150-180 Days
Plant Hardiness Zone - 2023Zone 5a : -20°F to -15°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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