Lanark, IL has a humid continental climate with hot, muggy summers and cold winters. Average temperatures range from the mid 30s (Fahrenheit) in January to the mid-80s in July. Annual precipitation is around 36 inches, with snowfall usually occurring between November and April. During summer months, Lanark experiences frequent thunderstorms which can bring heavy rain and sometimes hail or even tornadoes. Winters bring cold temperatures and some light snowfall, while spring is when everything comes alive as flowers begin to bloom and plants start to grow.
Lanark, Illinois gets 39 inches of rain, on average, per year. The US average is 38 inches of rain per year.
Lanark averages 31 inches of snow per year. The US average is 28 inches of snow per year.
On average, there are 196 sunny days per year in Lanark. The US average is 205 sunny days.
Lanark gets some kind of precipitation, on average, 113 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 84 degrees
Winter Low: the January low is 12
Rain: averages 39 inches of rain a year
Snow: averages 31 inches of snow a year