The calendar has caught up with the thermometer — summer has arrived in Chicago.
That’s right, spring is over — according to meteorologists. Though the summer solstice is June 21, experts prefer to track weather in four, three-month increments instead of astronomical seasons, which are defined by equinoxes and solstices.
WGN-Ch. 9 chief meteorologist Tom Skilling is frequently asked why forecasters favor meteorological seasons.
“I prefer meteorological winter — and the other three seasons: spring (March to May), summer (June to August) and fall (September to November) — because they are unvarying in their beginning and ending dates. This is essential in making comparisons between seasons (temperatures, for example) from one year to another. The data are always from identical periods of time,” Skilling said.
We take a look back with local weather experts at the past three months and chose key dates to highlight meteorological spring 2022′s significant events.
Though spring lacked record-breaking events, it was still notable for its unusualness, said Illinois state climatologist Trent Ford.
“Spring is typically a variable weather season, but this spring has been wild,” he wrote in an email to the Tribune. “April was cold, rainy, and gloomy. Temperatures were consistently 2-3 degrees below normal in April, but it was the consistent cloudiness and rain that was noteworthy. (O’Hare International Airport) had 21 days with measurable precipitation between late March and early May, which means that over that time period it rained on more days than it didn’t rain. It was also incredibly cloudy.”
A lunar eclipse on May 15 into May 16 was partially marred by clouds near the lakefront. A WMAQ-Ch. 5 meteorologist nicknamed a 42-day stretch of mostly cloudy days between March and April as “Sunless in Chicago.”
Then, Ford said, the “oven turned on.”
Warmest high temperature: First 90-degree days of 2022
A new daily record high of 90 degrees was reached at O’Hare International Airport (the city’s official recording site) on May 11 — almost a month earlier than normal, according to the National Weather Service. It was the earliest 90-degree temperature recorded since May 10, 2011.
The next day, the temperature topped out at 91 degrees.
“The absolute temperatures that week in northern Illinois were VERY unusual, but what was truly remarkable was how quickly we moved from persistently cool and cloudy to hot and humid,” Ford said. “This kind of flip in spring can be particularly dangerous for humans because we are not acclimated to the heat.”
Coldest high temperature: 23 degrees
Anyone who went downtown to watch the first dyeing of the Chicago River in two years due to the coronavirus pandemic can tell you — it was brisk. But it wasn’t the final bone-chilling day of the season.
O’Hare airport recorded the last freezing low temperature of spring on April 17 — Easter. That was just about normal, even though bundling up for the holiday is not.
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.
Highest daily rain accumulation: 1.54 inches
Short-lived tornadoes popped up in two rounds of severe weather with an EF0 identified in Oak Brook — the closest damage to the Chicago area.
Ford said the wet weather is quite the contrast from spring 2021.
“In fact, the total precipitation for March this year in Chicago (3.69 inches) was nearly that of the entire spring last year (3.75 inches),” Ford said.
The upside of all this rain — Illinois became drought-free on April 26 for the first time since March 2021. At least part of the state registered drought for the previous 55 consecutive weeks, which is the longest on record since the U.S. Drought Monitor began in 2000, according to Ford.
Highest daily snow accumulation: 2.9 inches
No records were broken by the light snow, but maybe a few spirits were.
The last measurable snowfall of spring 2022 was 0.2 of an inch recorded on April 18 at O’Hare. Remember, measurable snowfall is one-tenth of an inch or more on the ground, while anything less is considered a trace amount.
Accumulating snow of 0.1 of an inch or more has been recorded in four of the five past years on April 17 or later in Chicago, according to the National Weather Service. Normally, the last measurable snow occurs around April 2.
More rain — possibly: Ford credits the La Niña climate pattern, which has stuck around since last fall, for spring precipitation that could continue beyond the next few months. It’s the second consecutive year La Niña has occurred — known as a “double dip.”
“It’s unusual for a La Niña to hang on through summer, and even more unusual to go into a third consecutive La Niña —which we would if it hung on into fall,” he said.
Future thunderstorms, hail, flooding and tornadoes require good preparation: Brett Borchardt, meteorologist for the National Weather Service’s Chicago office, said June and July are typically the most active months locally for severe weather. Now, he said, it a good time to brush up on safety procedures and get a refresher on what outlooks, watches and warnings are issued by the weather service.
“Recall that 2021 also started slowly — we picked up the slack in June with the Naperville to Willow Springs EF-3 tornado,” he wrote in an email to the Tribune.