Rock Island, IL has a temperate climate with hot, muggy summers and cold winters. Average summer temperatures range from the mid-70s to low 80s Fahrenheit and winter temperatures often dip into the single digits. Precipitation is abundant throughout most of the year, with occasional snowfall during the winter months. The humidity levels tend to be high in the warmer months as well. With four distinct seasons, Rock Island offers a unique experience for its residents and visitors alike.
Rock Island, Illinois gets 37 inches of rain, on average, per year. The US average is 38 inches of rain per year.
Rock Island averages 28 inches of snow per year. The US average is 28 inches of snow per year.
On average, there are 198 sunny days per year in Rock Island. The US average is 205 sunny days.
Rock Island gets some kind of precipitation, on average, 115 days per year. Precipitation is rain, snow, sleet, or hail that falls to the ground. In order for precipitation to be counted you have to get at least .01 inches on the ground to measure.
Weather Highlights
Summer High: the July high is around 85 degrees
Winter Low: the January low is 15
Rain: averages 37 inches of rain a year
Snow: averages 28 inches of snow a year