Rock Island Illinois Climate Data

Monthly Average Climate Data for Rock Island Illinois

Switch Data to Fahrenheit
MonthAvg. LowAvg. HighAvg. Precip
January-9.6 °C-0.7 °C38.61 mm
February-7.6 °C1.8 °C44.96 mm
March-1.6 °C9 °C64.52 mm
April4.6 °C16.4 °C93.22 mm
May11.2 °C22.6 °C122.94 mm
June16.7 °C27.8 °C122.68 mm
July18.8 °C29.4 °C107.95 mm
August17.6 °C28.4 °C101.6 mm
September13 °C25.1 °C87.38 mm
October6.4 °C18 °C72.9 mm
November-0.3 °C9.6 °C58.17 mm
December-6.1 °C2.3 °C50.8 mm
Annual5.3 °C15.8 °C965.73 mm

Climate Data for Rock Island 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 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