Lanark Illinois Climate Data

Monthly Average Climate Data for Lanark Illinois

Switch Data to Celsius/Metric Units
MonthAvg. LowAvg. HighAvg. Precip
January11.8 °F29.1 °F1.52 in.
February15.5 °F33.5 °F1.71 in.
March25.9 °F45.8 °F2.24 in.
April36.3 °F59.7 °F3.79 in.
May48.1 °F71.3 °F4.44 in.
June58.0 °F80.5 °F5.23 in.
July61.3 °F83.3 °F4.62 in.
August59.1 °F82.0 °F3.76 in.
September50.6 °F75.9 °F3.54 in.
October39.2 °F63.0 °F2.81 in.
November28.3 °F47.2 °F2.15 in.
December18.0 °F34.4 °F1.88 in.
Annual37.7 °F58.8 °F37.69 in.

Climate Data for Lanark 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 ConditionsSevere Drought
Köppen Climate ClassificationDfb - Humid Continental Mild Summer, Wet All Year
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