Chicago Snowfall Totals & Accumulation Averages
This page pulls together information on when, how much and how often Chicago, Illinois has snow.
There are data and descriptions here of how many days it snows and the total amount of snowfall that Chicago usually gets. There are also monthly and yearly counts of the days that the city normally has heavy snowstorms and deep snow accumulated on the ground. Plus there's information on when Chicago can expect the first and last snowfalls of the season.
All the numbers are averages, based on climate data gathered from 1981 to 2010 at the Chicago O'Hare International Airport.
How Often it Snows in Chicago
The O'Hare Airport has more snowy days, 28.5 a year, than other places in the Chicago area that record snowfall. Chicago's Midway Airport averages 26.7 days annually with snow, while the Botanical Gardens have 22.3 days.
Of the three locations, Midway Airport gets the most total snowfall, at 37.1 inches yearly, while the Botanical Gardens has the least amount at 33.4 inches.
This first table lists monthly and yearly totals for amount of snow and how many days it snows at least 0.1 inches (0.25 centimetres) at O'Hare.
These averages don't show how much Chicago's snowfall varies from year to year.
In December, for instance, one in four years totals over 10.4 inches of snow. Another 25 percent of years receive less than 3.4 inches for the month.
Similarly in January, fresh snowfall in the heaviest years amounts to 15.5 inches or more, while the lightest years get five inches or less.
Snow in February ranges from over 15.1 inches in heavy snowfall years to under 2.3 inches in light years.
When Chicago Has Its First & Last Snowfalls
Over the long-term Chicago has averaged a dusting of 0.3 inches of snow during October. But in most years October has no snow. Typically, just once in every five years see snow that early.
Chicago's first snowfall of winter usually arrives in November. For at least one in four years, snow doesn't arrive until December.
The season's last snowfall typically happens in April, which most years amounts to less than a quarter inch.
Chicago is normally free of snow every year from May to September.
How Many Snowstorms Chicago Has
Chicago gets snow more often than most places in Illinois. But most days with snowfall in Chicago result in just a skiff of less than an inch left on the ground. Normally on 12 days a year at least an inch of snow lands in one day.
Snowstorms of over five inches a day occur just once a year on average. Major blizzards that dump ten inches or more in one day are rare events, happening about once a decade.
How Much Snow Normally Accumulates in Chicago
For about half of winter days, Chicago has at least an inch of snow on the ground.
Snow mostly accumulates during January. Typically, on six days in January and another five in February, the snow covering Chicago gets to five or more inches deep. But for just a couple days a winter does the snowpack top ten inches.
National Climatic Data Center. NOAA's 1981-2010 Climate Normals.