Waterloo, IL has a humid continental climate, with warm and humid summers and very cold winters. Precipitation is relatively evenly distributed throughout the year, with occasional peaks in spring and autumn. Average temperatures can vary greatly from season to season; summer highs often reach into the mid-80s while winter lows may drop into the single digits and below. Snowfall can be quite heavy at times during the winter months. The area also experiences frequent thunderstorms during the warmer months, typically brought on by passing weather fronts originating in the Midwest.
Waterloo, Illinois gets 43 inches of rain, on average, per year. The US average is 38 inches of rain per year.
Waterloo averages 12 inches of snow per year. The US average is 28 inches of snow per year.
On average, there are 202 sunny days per year in Waterloo. The US average is 205 sunny days.
Waterloo gets some kind of precipitation, on average, 100 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 88 degrees
Winter Low: the January low is 22
Rain: averages 43 inches of rain a year
Snow: averages 12 inches of snow a year