Chicago weather: When to expect the last freeze and snow of spring

This morning’s rain turning into snow makes it feel more like winter than spring in Chicago.

And though snow didn’t arrive until almost the beginning of 2022, many wonder when its threat will finally dissipate and temperatures will warm up for good — perennial questions for Midwesterners this time of year.

For these answers, we look back at normal occurrences for these weather phenomena using data from the National Weather Service. And we take a look at the forecast for the rest of spring.

Chicago’s normal last freeze

If the past is any indication of the present, then the Chicago area can still expect the possibility of low temperatures hovering near or below freezing for the next week or two.

The final freeze of spring — when the temperature is 32 degrees or lower — is usually observed April 5-15 in the city and a week or more later in the surrounding suburbs. Yet, these dates are highly variable.

Chicago’s earliest last freeze on record took place on March 19, 1925. Its latest — May 25, 1992. O’Hare International Airport, the city’s official recording site, normally experiences its last freeze by April 23.

Tracking the last significant snowfall

Looking back at more than 130 years of local weather data, Chicago has experienced its final measurable snow — that’s 0.1 inches or more — as early as Feb. 28 (in 1994) and as late as May 11 (in 1966).

That’s why April 2 is the date of the normal last snowfall in Chicago. Remember, measurable snowfall is one-tenth of an inch or more on the ground, while anything less is considered a trace amount.

Normally, the area’s final snow of the spring takes place in March or April.

In case you want one more significant snowfall — it’s possible

Chicago’s largest last snow of the winter was 7.1 inches on Easter Sunday, March 29, 1964. It was also the heaviest Easter snowfall on record and the most significant snowfall of the 1963-64 season.

“Before it ended late in the afternoon, the snow brought hazardous driving conditions and a rash of minor traffic accidents in the Chicago area. However, it failed to prevent large numbers of Chicagoans from attending Easter services,” the Chicago Tribune reported in the next day’s paper.

Since 1871, snowfall of more than a trace has been recorded just 10 times on Easter.

Chicago had a snow depth of 6 inches — the deepest ever for the holiday — on April 4, 1920.

What to expect this spring

The La Niña climate pattern is still in effect for the second consecutive year, or a “double dip,” as meteorologists call it.

As a result, the latest outlook from the National Weather Service’s Climate Prediction Center shows the Chicago area could experience warmer weather and more rain — or not — through June.

“La Niña falls tend to be a bit drier and warmer across the Midwest, but there is A LOT of variability between La Niña years,” Trent Ford, Illinois state climatologist, wrote in an email to the Tribune.