McLean Illinois Climate Data

Monthly Average Climate Data for McLean Illinois

Switch Data to Celsius/Metric Units
MonthAvg. LowAvg. HighAvg. Precip
January16.9 °F33.4 °F2.24 in.
February20.4 °F38.3 °F1.98 in.
March29.7 °F50.1 °F2.68 in.
April40.5 °F63.4 °F3.85 in.
May52.1 °F73.9 °F4.46 in.
June61.6 °F82.7 °F4.43 in.
July64.6 °F85.7 °F4.06 in.
August62.4 °F83.9 °F3.63 in.
September54.5 °F79.0 °F3.31 in.
October42.9 °F66.0 °F3.34 in.
November31.9 °F51.0 °F2.84 in.
December22.7 °F38.4 °F2.33 in.
Annual41.7 °F62.2 °F39.15 in.

Climate Data for McLean Illinois

Average First Frost DateOct. 11 - Oct. 20
Average Last Frost DateMay 1 - May 10
Average Days With Frost100-125 Days
Plant Hardiness Zone - 2023Zone 6a : -10°F to -5°F
Plant Hardiness Zone - 2012Zone 5b : -15°F to -10°F
Current Drought ConditionsModerate Drought
Köppen Climate ClassificationDfa - Humid Continental Hot Summers With Year Around Precipitation
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