Rock Island Illinois Climate Data

Monthly Average Climate Data for Rock Island Illinois

Switch Data to Celsius/Metric Units
MonthAvg. LowAvg. HighAvg. Precip
January14.8 °F30.7 °F1.52 in.
February18.4 °F35.2 °F1.77 in.
March29.1 °F48.2 °F2.54 in.
April40.3 °F61.5 °F3.67 in.
May52.1 °F72.6 °F4.84 in.
June62.1 °F82.0 °F4.83 in.
July65.8 °F85.0 °F4.25 in.
August63.6 °F83.2 °F4.0 in.
September55.4 °F77.2 °F3.44 in.
October43.5 °F64.4 °F2.87 in.
November31.4 °F49.2 °F2.29 in.
December21.0 °F36.2 °F2.0 in.
Annual41.5 °F60.5 °F38.02 in.

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 : -15°F to -10°F
Plant Hardiness Zone - 2012Zone 5b : -15°F to -10°F
Current Drought ConditionsAbnormally Dry
Köppen Climate ClassificationDfa - Humid Continental Hot Summers With Year Around Precipitation