At 65 degrees, Chicago breaks century-old record for warmest Feb. 16 in history

After a snow-drenched and typically frigid January, Chicago is having fun with a downright balmy – even record-breaking – begin to the week.

However do not pack your sweaters but.

The glimpse of spring will stay only a style as temperatures this weekend return to the chilly situations extra typical of this time of yr, climate officers say.

O’Hare Worldwide Airport reached a excessive of 65 levels on Monday, making it Chicago’s warmest February on report on Feb. 16, based on Nationwide Climate Service information. The earlier bar was 58 levels in 1921.

On common, the conventional temperature on February 16 is 28.9 levels, with the common temperature for the month additionally within the mid to excessive 20s, based on climate service information.

A lot of this winter has been outlined by what climate officers think about “northwesterly circulation,” which permits air from Canada and the Arctic to circulation south, mentioned Brett Borchardt, a senior meteorologist on the Nationwide Climate Service in Chicago. This climate sample has led to record-breaking snowfall, temperatures below freezing And huge storms.

After years of little snow within the Chicago space, this winter appears to contradict scientific reviews that winters are getting hotter. However trends of the past decades point out an total warming of common temperatures in all seasons as a result of human actions such because the burning of fossil fuels, which launch heat-trapping gases into the environment. And that total warming doesn’t rule out some occasional outliers, together with excessive chilly and winter storms.

Based on Illinois State Climatologist Trent Ford, day-to-day temperature variation is highest in January and February.

“It is one thing we see just about each season,” he mentioned.

However what’s “superb,” Ford continued, is how massive the magnitude of that variability is starting to develop into. Ford famous that the area was 20 to 30 levels under common for a every day most temperature in late January. Now temperatures have turned to a particularly delicate temperature in mid-February that has not been seen for many years.

That hole is indicative of the altering local weather within the Midwest, Ford mentioned.

“If I get a day like that, clearly I need to be exterior and luxuriate in it as a result of it has been so chilly for therefore lengthy,” Ford mentioned. “However what’s actually on my thoughts… (is) the truth that we have (damaged) a report, as a result of that variability is on prime of a warming development, making it extra doubtless that we may have these eye-popping temperatures in mid-February.”

Based on Borchardt, the flash of heat climate would final at the least all week. Tuesday will see barely cooler temperatures within the mid-50s, adopted by a fair hotter Wednesday, which may see highs within the mid-60s – if not somewhat hotter. The report for February 18 is 70 levels from 2017.

However actuality settles in by Friday and into the weekend, with daytime highs dropping again into the 30s and 40s, Borchardt mentioned. The spring-like temperatures are a perform of a “favorable sample” of southwesterly winds which can be carrying unusually heat air into the Chicago space, Borchardt mentioned.

Final week the Trump administration has dismantled the country’s ability to combat climate change when it withdrew the scientific willpower underlying federal greenhouse fuel rules, triggering one of the crucial dramatic reversals in U.S. local weather coverage.

The administration final week too denied the state’s request for a disaster declaration that might have supplied federal help to hundreds of residents hit by heavy rains and flooding final summer season, a choice that Gov. JB Pritzker described as politically pushed.

Ford mentioned that on days like Monday, when the nice and cozy climate is a welcome change after weeks of chilly, it is troublesome to see the real-time impression of the general warming. However there’s a consequence of creating delicate durations extra widespread in winter, he mentioned, from creating extra favorable situations for invasive species and animals to affecting plant development and growth.

And strikes like final week’s, Ford mentioned, make progress on local weather harder.

Adriana Perez of the Chicago Tribune contributed.

tkenny@chicagotribune.com