McHenry County, IL has a continental climate with four distinct seasons. Summers are typically hot and humid with temperatures reaching the upper 80s and low 90s. Winters can be cold and snowy, with temperatures ranging from the mid-teens to the low 30s. Spring is often mild and wet while fall tends to be a pleasant season of colorful foliage. Precipitation is spread throughout the year in McHenry County, though summer thunderstorms often bring heavy rainfall. Snowfall generally comes in late December through early spring months.
McHenry County, Illinois gets 37 inches of rain, on average, per year. The US average is 38 inches of rain per year.
McHenry County averages 35 inches of snow per year. The US average is 28 inches of snow per year.
On average, there are 190 sunny days per year in McHenry County. The US average is 205 sunny days.
McHenry County gets some kind of precipitation, on average, 116 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 83 degrees
Winter Low: the January low is 13
Rain: averages 37 inches of rain a year
Snow: averages 35 inches of snow a year