Washington Illinois Climate Data

Monthly Average Climate Data for Washington Illinois

Switch Data to Fahrenheit
MonthAvg. LowAvg. HighAvg. Precip
January-9 °C0.3 °C55.37 mm
February-7.1 °C3 °C53.09 mm
March-1.7 °C9.8 °C65.02 mm
April4.3 °C17.1 °C96.77 mm
May10.8 °C22.9 °C118.62 mm
June16.2 °C27.9 °C111.51 mm
July17.9 °C29.7 °C94.74 mm
August16.8 °C28.7 °C88.9 mm
September12.3 °C25.9 °C87.88 mm
October5.9 °C18.6 °C80.01 mm
November-0.3 °C10.3 °C70.36 mm
December-5.8 °C3.2 °C53.59 mm
Annual5 °C16.5 °C975.86 mm

Climate Data for Washington 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 6a : -23.3°C to -20.6°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
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