Janesville Wisconsin Climate Data

Monthly Average Climate Data for Janesville Wisconsin

Switch Data to Celsius/Metric Units
MonthAvg. LowAvg. HighAvg. Precip
January12.0 °F27.9 °F1.57 in.
February15.0 °F31.8 °F1.63 in.
March25.5 °F44.1 °F2.07 in.
April36.2 °F57.4 °F3.66 in.
May47.9 °F69.2 °F4.22 in.
June57.7 °F79.2 °F5.33 in.
July61.8 °F82.7 °F3.79 in.
August60.0 °F81.1 °F4.26 in.
September51.7 °F74.4 °F3.63 in.
October40.0 °F61.2 °F2.92 in.
November29.1 °F46.1 °F2.31 in.
December18.6 °F33.4 °F1.88 in.
Annual38 °F57.4 °F37.27 in.

Climate Data for Janesville Wisconsin

Average First Frost DateOct. 11 - Oct. 20
Average Last Frost DateMay 11 - May 20
Average Days With Frost125-150 Days
Plant Hardiness Zone - 2023Zone 5b : -15°F to -10°F
Plant Hardiness Zone - 2012Zone 5a : -20°F to -15°F
Current Drought ConditionsAbnormally Dry
Köppen Climate ClassificationDfa - Humid Continental Hot Summers With Year Around Precipitation
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