McHenry Illinois Climate Data

Monthly Average Climate Data for McHenry Illinois

Switch Data to Fahrenheit
MonthAvg. LowAvg. HighAvg. Precip
January-10.4 °C-1.6 °C45.21 mm
February-8.8 °C0.6 °C46.74 mm
March-3.5 °C7 °C56.13 mm
April2.3 °C14.3 °C95.25 mm
May8.4 °C20.7 °C118.87 mm
June14 °C26.1 °C124.97 mm
July16.6 °C28.3 °C98.55 mm
August15.7 °C27.3 °C98.3 mm
September11.2 °C23.6 °C90.93 mm
October4.7 °C16.3 °C79.76 mm
November-1.2 °C8.3 °C61.21 mm
December-6.9 °C1.4 °C50.8 mm
Annual3.5 °C14.4 °C966.72 mm

Climate Data for McHenry 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 : -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