Welcome to summer, Chicago.
But, wait, isn’t summer officially more than two weeks away?
Yes, the summer solstice takes place at 10:32 p.m. June 20. Yet Monday marked the beginning of spring for weather watchers. Why is that?
Consistency.
WGN-TV chief meteorologist Tom Skilling is frequently asked why forecasters prefer to follow meteorological seasons — which are separated into four three-month increments — instead of astronomical seasons — which are defined by equinoxes and solstices.
Given that consistency, how did spring 2021 compare with the previous 149 years of Chicago weather data? What follows is a look back at significant events of our meteorological spring.
Temperature: Warm with a few, new daily record highs
This was the seventh warmest meteorological spring on record in Chicago, with a mean average temperature of 52.1 degrees, according to the National Weather Service.
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Rain: Not enough as we head into warmer months
The real concern of our meteorological spring is precipitation — the lack of it.
This was the third driest spring on record in Chicago with just 3.75 inches of rain recorded from March through May, according to the National Weather Service. That’s 6.94 inches below normal.
The deficit is even worse when analyzing total precipitation in 2021. The first five months of this year constitute the second driest January to May on record at O’Hare International Airport (6.95 inches) — 7.7 inches below normal. That’s the driest since 1989, says Trent Ford, Illinois state climatologist.
Ford said severe drought conditions cover significant chunks of Cook, Lake, McHenry, DuPage and Kane counties. With a forecast of minimal precipitation in the weeks ahead, the impacts on shrubs, trees, specialty crop agriculture and natural ecosystems in the Chicago metro area could increase.
Brett Borchardt, meteorologist for the National Weather Service’s Chicago office, said we’ve missed out on thunder, lightning and flash floods this year. The weather service put out its last severe weather alert for Chicago on Nov. 10, 2020 — more than 200 days ago.
June is our most active month for severe weather and flash flooding — seven days of it, on average, according to Borchardt.
“We’re not complaining about our lack of severe weather,” Borchardt said. “It’s nevertheless remarkable.”
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Snow: A brief ‘third winter’
Chicago received its last significant snowfall of the 2020-21 winter season on March 15. A record high of 69 degrees was recorded at O’Hare the previous week, causing some on social media to call the 1.8-inch snow total the city’s “third winter.”
That was understandable. The area’s first snowfall of the 2020-21 winter season happened Nov. 24, 2020 — 113 days prior — so almost four months later some people were ready to say goodbye to the fluffy stuff.
Yet, meteorological spring’s snow total was 5 inches below normal.
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Sources: National Weather Service Chicago; Illinois State Climatologist; Tribune reporting and archives
