Winnetka Illinois Climate Data

Monthly Average Climate Data for Winnetka Illinois

Switch Data to Fahrenheit
MonthAvg. LowAvg. HighAvg. Precip
January-7.3 °C-0.1 °C54.36 mm
February-5.7 °C1.9 °C51.82 mm
March-0.9 °C7.2 °C55.63 mm
April4.5 °C13.6 °C96.52 mm
May10.2 °C19.8 °C116.84 mm
June15.8 °C25.3 °C109.47 mm
July19.6 °C27.9 °C94.49 mm
August19.3 °C27.1 °C103.63 mm
September15.2 °C23.4 °C89.15 mm
October8.3 °C16.9 °C88.65 mm
November1.7 °C9.1 °C66.8 mm
December-3.9 °C2.8 °C57.91 mm
Annual6.4 °C14.6 °C985.27 mm

Climate Data for Winnetka Illinois

Average First Frost DateOct. 21 - Oct. 31
Average Last Frost DateMay 1 - May 10
Average Days With Frost100-125 Days
Plant Hardiness Zone - 2023Zone 6a : -23.3°C to -20.6°C
Plant Hardiness Zone - 2012Zone 5b : -26.1°C to -23.3°C
Current Drought ConditionsModerate Drought
Köppen Climate ClassificationDfa - Humid Continental Hot Summers With Year Around Precipitation
2024 plantmaps.com