DeKalb Illinois Climate Data

Monthly Average Climate Data for DeKalb Illinois

Switch Data to Fahrenheit
MonthAvg. LowAvg. HighAvg. Precip
January-10.7 °C-1.9 °C43.18 mm
February-8.7 °C0.4 °C43.94 mm
March-3.2 °C7.3 °C56.39 mm
April2.7 °C14.8 °C87.38 mm
May9.2 °C21.2 °C124.46 mm
June14.7 °C26.5 °C116.33 mm
July16.8 °C28.2 °C97.03 mm
August15.6 °C27.2 °C100.33 mm
September10.9 °C23.9 °C85.6 mm
October4.4 °C16.8 °C75.44 mm
November-1.4 °C8.3 °C60.2 mm
December-7.3 °C1.2 °C50.29 mm
Annual3.6 °C14.5 °C940.57 mm

Climate Data for DeKalb 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 : -26.1°C to -23.3°C
Plant Hardiness Zone - 2012Zone 5b : -26.1°C to -23.3°C
Current Drought ConditionsNormal
Köppen Climate ClassificationDfa - Humid Continental Hot Summers With Year Around Precipitation