Hartland Illinois Climate Data

Monthly Average Climate Data for Hartland Illinois

Switch Data to Fahrenheit
MonthAvg. LowAvg. HighAvg. Precip
January-10.2 °C-1.6 °C43.69 mm
February-8.7 °C0.7 °C46.48 mm
March-3.4 °C7.2 °C57.91 mm
April2.2 °C14.4 °C96.77 mm
May8.7 °C20.9 °C116.84 mm
June14.1 °C26.2 °C128.27 mm
July16.4 °C28.2 °C100.84 mm
August15.4 °C27.3 °C100.33 mm
September11.1 °C23.6 °C92.2 mm
October4.8 °C16.3 °C74.93 mm
November-1.2 °C8.2 °C61.98 mm
December-7 °C1.2 °C51.31 mm
Annual3.5 °C14.4 °C971.55 mm

Climate Data for Hartland Illinois

Average First Frost DateOct. 11 - Oct. 20
Average Last Frost DateApr. 21 - Apr. 30
Average Days With Frost100-125 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 ConditionsAbnormally Dry
Köppen Climate ClassificationDfa - Humid Continental Hot Summers With Year Around Precipitation
2025 plantmaps.com