Olney, IL has a humid continental climate, with cold winters and hot humid summers. Average temperatures range from 22°F in January to 78°F in July. Precipitation is distributed fairly evenly throughout the year, averaging around 43 inches per year. Summers are often hot and humid with frequent thunderstorms and occasional tornadoes. Winters are usually cold and dry, with occasional snowfall. Spring and fall have moderate temperatures and plenty of rainfall. Olney's location in the Midwest results in it being situated in a transitional climate zone between the more extreme climates of the northern Great Plains and the cooler climates of the Appalachian region.
Olney, Illinois gets 45 inches of rain, on average, per year. The US average is 38 inches of rain per year.
Olney 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 Olney. The US average is 205 sunny days.
Olney gets some kind of precipitation, on average, 109 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 87 degrees
Winter Low: the January low is 20
Rain: averages 45 inches of rain a year
Snow: averages 12 inches of snow a year