Illinois has a varied climate depending on the region. In the northern part of the state, the weather is often cold with hot summers and moderate to heavy winter snowfall. In the southern areas, the climate is more humid and subtropical, with hot, humid summers and mild winters. Overall, Illinois enjoys four distinct seasons that bring everything from beautiful spring flowers to chilly winter snowfalls. Average temperatures range from highs of 90 degrees Fahrenheit in summer to lows of around 20 degrees Fahrenheit in winter. Precipitation also varies widely by region, but generally averages between 35-45 inches per year across the state.
Illinois, Illinois gets 40 inches of rain, on average, per year. The US average is 38 inches of rain per year.
Illinois averages 22 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 Illinois. The US average is 205 sunny days.
Illinois gets some kind of precipitation, on average, 108 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.
Summer High: the July high is around 86 degrees
Winter Low: the January low is 17
Rain: averages 40 inches of rain a year
Snow: averages 22 inches of snow a year
BESTPLACES COMFORT INDEX
Illinois's annual BestPlaces Comfort Index of 7.1 (10=best) indicates it is about average compared to other states in the United States.
8.4 / 5
Summer / Winter
September, June and May are the most pleasant months in the state of Illinois, while January and December are the least comfortable months.