Millbrook Illinois Climate Data

Monthly Average Climate Data for Millbrook Illinois

Switch Data to Celsius/Metric Units
MonthAvg. LowAvg. HighAvg. Precip
January15.4 °F30.9 °F1.84 in.
February18.3 °F34.9 °F1.78 in.
March28.1 °F47.0 °F2.35 in.
April38.7 °F60.2 °F3.78 in.
May49.9 °F71.5 °F4.68 in.
June59.9 °F80.8 °F4.65 in.
July63.5 °F84.0 °F3.93 in.
August61.7 °F82.1 °F3.86 in.
September53.7 °F76.7 °F3.42 in.
October41.8 °F63.7 °F3.28 in.
November31.2 °F48.9 °F2.51 in.
December21.2 °F36.2 °F2.11 in.
Annual40.3 °F59.7 °F38.19 in.

Climate Data for Millbrook Illinois

Average First Frost DateOct. 11 - Oct. 20
Average Last Frost DateMay 1 - May 10
Average Days With Frost125-150 Days
Plant Hardiness Zone - 2023Zone 5b : -15°F to -10°F
Plant Hardiness Zone - 2012Zone 5b : -15°F to -10°F
Current Drought ConditionsAbnormally Dry
Köppen Climate ClassificationDfa - Humid Continental Hot Summers With Year Around Precipitation
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