Algonquin Illinois Climate Data

Monthly Average Climate Data for Algonquin Illinois

Switch Data to Celsius/Metric Units
MonthAvg. LowAvg. HighAvg. Precip
January14.5 °F30.1 °F1.92 in.
February17.3 °F34.0 °F1.9 in.
March26.9 °F45.5 °F2.18 in.
April37.2 °F58.4 °F3.75 in.
May48.2 °F69.8 °F5.04 in.
June58.2 °F79.7 °F4.97 in.
July63.0 °F83.7 °F4.09 in.
August61.5 °F81.6 °F4.1 in.
September53.5 °F75.0 °F3.52 in.
October41.8 °F62.0 °F3.2 in.
November30.7 °F47.5 °F2.49 in.
December20.6 °F35.5 °F2.12 in.
Annual39.5 °F58.6 °F39.28 in.

Climate Data for Algonquin Illinois

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 5b : -15°F to -10°F
Current Drought ConditionsModerate Drought
Köppen Climate ClassificationDfa - Humid Continental Hot Summers With Year Around Precipitation