When can southwest IL residents expect spring weather? Forecasters, almanac outlook

Meredith Howard
·3 min read

With low temperatures expected to reach minus 2 degrees Fahrenheit Sunday night, metro-east and St. Louis region residents may be wondering when things will warm up.

“I wish we had warmer weather coming, but we do not,” National Weather Service St. Louis meteorologist Lydia Jaja told the News-Democrat Tuesday. “We actually have much colder weather coming through the weekend. After this storm system we have kind of a blast of arctic air in the metro.”

The first day of spring is March 19, so sunnier weather may still be a ways off, but when exactly does the metro-east typically warm up? Here’s what to know.

When can southwest Illinois expect springtime weather?

The overall average temperature in Belleville surpasses 50 degrees in April, but things will gradually warm up from now until then.

The NWS reports the metro-east and St. Louis region has a 33% to 40% chance of above-normal temperatures and below-normal precipitation from January to March.

Here are precipitation and temperature normals for Belleville, using NWS data from 1991 to 2020:

January:

  • Total normal precipitation: 2.56 inches

  • Average overall temperature: 33.6 degrees

  • Average low temperature: 24.3 degrees

  • Average high temperature: 42.9 degrees

February:

  • Total normal precipitation: 2.16 inches

  • Average overall temperature: 38.3 degrees

  • Average low temperature: 28 degrees

  • Average high temperature: 48.6 degrees

March:

  • Total normal precipitation: 3.44 inches

  • Average overall temperature: 47.8 degrees

  • Average low temperature: 36.3 degrees

  • Average high temperature: 59.2 degrees

April:

  • Total normal precipitation: 4.9 inches

  • Average overall temperature: 58.3 degrees

  • Average low temperature: 46 degrees

  • Average high temperature: 70.6 degrees

May:

  • Total normal precipitation: 5.05 inches

  • Average overall temperature: 67.7 degrees

  • Average low temperature: 56.3 degrees

  • Average high temperature: 79.1 degrees

June:

  • Total normal precipitation: 4.62 inches

  • Average overall temperature: 75.9 degrees

  • Average low temperature: 64.5 degrees

  • Average high temperature: 87.3 degrees

What does the Farmers’ Almanac predict?

The metro-east spans two winter predictions from the Farmer’s Almanac, with southwestern Illinois closer to the “cold, stormy” outlook and St. Louis near the “cold, average snowfall” forecast.

Although spring officially begins in March, the almanac predicts cold weather will persist that month.

“March will remind us that the Brrr is Back and won’t let go too easily,” the almanac website reads. “March’s extended forecast calls for wild swings in the thermometer, especially in the East. And March could go out like a lion, with stormy conditions nationwide.”

The Farmers’ Almanac makes predictions based on a mysterious formula that considers factors such as planetary positioning, sunspot activity and tidal action of the moon.

“The only person who knows the exact formula is the Farmers’ Almanac weather prognosticator who goes by the pseudonym of Caleb Weatherbee,” the organization’s website says. “To protect this proprietary formula, the editors of the Farmers’ Almanac prefer to keep both Caleb’s true identity and the formula a closely guarded brand secret.”

The almanac has provided extended forecasts since 1818, according to its website.