Rock City Illinois Climate Data

Monthly Average Climate Data for Rock City Illinois

Switch Data to Celsius/Metric Units
MonthAvg. LowAvg. HighAvg. Precip
January11.7 °F27.8 °F1.55 in.
February15.1 °F31.9 °F1.63 in.
March25.5 °F44.2 °F2.1 in.
April36.3 °F57.9 °F3.71 in.
May48.1 °F69.5 °F4.25 in.
June58.2 °F79.1 °F5.36 in.
July61.7 °F82.2 °F4.06 in.
August59.8 °F80.6 °F3.96 in.
September51.4 °F74.0 °F3.81 in.
October39.9 °F61.1 °F2.94 in.
November28.8 °F46.0 °F2.28 in.
December18.3 °F33.2 °F1.87 in.
Annual37.9 °F57.3 °F37.52 in.

Climate Data for Rock City Illinois

Average First Frost DateOct. 1 - Oct. 10
Average Last Frost DateMay 11 - May 20
Average Days With Frost125-150 Days
Plant Hardiness Zone - 2023Zone 5a : -20°F to -15°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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