‘Third winter,’ severe drought, tornadoes and the long wait for snow: Chicago’s biggest weather stories of 2021
Add snow to the list of items available only in spurts due to supply-chain issues in 2021.
Chicago was inundated with it in late January. December, however, marked the latest date of a first snowfall in Chicago history going back to 1885.
Severe drought crept into suburban Chicago for the first time since 2012. Tornadoes spawned throughout the summer — including an EF-3 on Father’s Day with wind speeds estimated from 136 mph to 165 mph. A warm, mild fall allowed children to trick-or-treat without wearing parkas and delayed the city’s first freeze until Nov. 2.
Here are the biggest events in Chicago weather this year, with insights by Brett Borchardt, meteorologist for the National Weather Service’s Chicago office, and Trent Ford, Illinois state climatologist.
Why track by meteorological season?
Consistency.
WGN-Ch. 9 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.
“I prefer meteorological winter — and the other three seasons: spring (March through May), summer (June through August) and fall (September through November) — because they are unvarying in their beginning and ending dates,” Skilling wrote in the Tribune in 2018. “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.”
Winter 2020-21: December through February
Average high temperature: 33.5 degrees (0.1 degree below normal).
Rain: 5.75 inches — (0.02 inches below normal).
Snow: 46.3 inches — (slightly more than 18 inches above normal).
Complete meteorological season summary from the National Weather Service.
After a balmy start to the season, temperatures dropped below freezing for 17 consecutive days in early February — the first time temperatures plunged below normal for more than two consecutive days during meteorological winter.
Remember when the alignment of Jupiter and Saturn was supposed to be visible on the winter solstice? Clouds and a trace of rain ruined the show.
Though no Top 10 seasonal records were set for Chicago during the season, significant snowfall totals arrived in late January and continued to mid-February. There were nine consecutive days with measurable snowfall in Chicago — tying the record for most with Feb. 3-11, 2018.
“Throughout January I was hearing about ‘snow drought’ and ‘near record mild winter’ because of the lack of significant winter weather,” Ford wrote in an email to the Tribune. “Then the area experienced its ninth snowiest February on record. The persistent cold temperatures kept the snow around for a while too.”
Ten or more inches of snow blanketed the ground at O’Hare International Airport, the city’s official recording site, for 25 days — the fourth-longest stretch in Chicago’s recorded history.
A peak snow depth of 21 inches at O’Hare on Feb. 16 was the deepest in a decade — since the Groundhog Day Blizzard of 2011 — and tied for fourth deepest snowpack on record.
The snowiest three weeks (Jan. 26-Feb. 15, 2021) since 1979 left 34.1 inches of snow at O’Hare International Airport, the city’s official recording site.
“In all, Chicago saw 34.5 inches of snow in just three weeks between late January and mid-February, only 1.5 inches below the 30-year normal total snowfall for the entire season,” Ford said.
A record daily snowfall of 6.1 inches was recorded on Feb. 15, President’s Day.
Spring 2021: March through May
Average high temperature: 61.4 degrees (2.6 degrees above normal).
Rain: 3.75 inches — (6.94 inches below normal).
Snow: 1.8 inches — (5.0 inches below normal).
Complete meteorological season summary from the National Weather Service.
It 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.
Chicago’s total snowfall accumulation for the 2020-21 winter season was 48.8 inches. On Twitter, some locals joked that Chicago had entered its “third winter” after 1.8 inches of snow fell at O’Hare on March 15, which was the last significant snow of the season. A record high of 69 degrees was recorded at the airport the previous week.
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.
The real concern of meteorological spring was the lack of precipitation.
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.
McHenry, Lake, Kane and DuPage counties experienced severe drought in May. For Cook County, it was the first time in almost a decade — since August 2012 — that severe drought had been reported there.
Borchardt said spring was also lacking thunder, lightning and flash floods with the weather service putting its last severe weather alert for Chicago on Nov. 10, 2020 — more than 200 days ago. By the end of May, thunder had only been reported twice in 2021.
June is usually Chicago’s most active month for severe weather and flash flooding — seven days of it, on average, he said.
“We’re not complaining about our lack of severe weather,” Borchardt said. “It’s nevertheless remarkable.”
Summer 2021: June through August
Average high temperature: 84.1 degrees (1.6 degrees above normal).
Rain: 13.19 inches — (1.13 inches above normal).
Complete meteorological season summary from the National Weather Service.
Chicago’s summer weather — tied with 1953 and 1973 for the eighth hottest on record — was its most dramatic of the year. Four of the top 10 warmest summers on record in Chicago have occurred since 2010 (2010, 2012, 2020, 2021).”
Summer was also very humid, Ford noted. “The average summer dew point temperature in Chicago was 65.4 degrees, the fourth highest on record (dew point record goes back to 1947),” he wrote in an email.
Some Chicagoans experienced a shake at 2:18 p.m. on June 17 — but it wasn’t due to a storm. A magnitude 3.8 earthquake was reported about 2 miles west of Bloomingdale, Indiana.
According to the Illinois State Geological Survey, earthquakes occur in Illinois about once a year. A 2.4-magnitude earthquake occurred near McHenry on Jan. 30, 2012. The last damaging earthquake happened in downstate Illinois in June 1987.
Borchardt said the majority of severe weather experienced during 2021 happened in June (nine days) and August (eight days) — after no severe weather reports issued at all in May. The severe weather season got off to a slow start, with the first “severe weather day” not occurring until April 29, he said.
Damaging winds and tornadoes were significant, including an EF-3 that tore through Naperville, Woodridge and Darien with wind speeds estimated between 136 mph and 165 mph on Father’s Day, June 20. Eight people were injured and more than 200 structures were damaged by the storm.
It was the first tornado of its size to impact the Chicago area since another EF-3 passed through Coal City on June 22, 2015, Borchardt said.
“The fact that it was a strong tornado that moved through a densely populated area at night and there were no fatalities is incredible,” Ford wrote in an email. “Certainly, a sign of folks’ severe weather preparedness and the hard work the National Weather Service and local EMS does to make their communities weather-ready.”
The first tornado warning in 11 years was issued for downtown Chicago just five days later as four tornadoes and flash floods moved through the area. In August, 10 tornadoes touched down and clusters of thunderstorms caused widespread wind damage throughout northern Illinois.
Tornadoes during meteorological summer:
June 20: Four tornadoes including the Naperville to Willow Springs EF-3.
June 25-26: Four tornadoes, and the first tornado warning to include downtown Chicago since June 23, 2010.
Aug. 9-12: Waves of severe weather, including 10 tornadoes, widespread wind damage, and significant flash flooding in Gibson City. (Aug. 9, Aug. 10-11 and Aug. 12 event summaries)
The severe weather failed to dropped slightly more rain than normal. Drought, however, expanded during the summer and was the worst in northern Chicago suburbs and along the Illinois-Wisconsin state line, Borchardt said.
“Although the drought has weakened since midsummer, the Chicagoland area is still in a 6-to-12-inch precipitation deficit for the year to date,” Ford said.
Fall 2021: September through November
Average high temperature: 64.9 degrees (2.7 degrees above normal).
Rain: 7.71 inches — (1.33 inches below normal).
Snow: No measurable snow.
Complete meteorological season summary from the National Weather Service.
Summer’s active weather was followed by a warm, mild fall.
Chicago was so warm overnight this year that the city observed 80 nights where the temperature did not fall below 65 degrees, the third most on record and the most since 1921, Ford said.
Chicago had no reports of hail larger than 2 inches in diameter until Sept. 7, which is unusual. “We typically average three to four reports every year,” Borchardt said.
The city recorded 11 nights in October where the temperature did not reach below 60 degrees, compared to two or three on average, Ford said. He also said fall leaf color across northern Illinois and southern Wisconsin was delayed by these warm nights.
It was so warm Chicago didn’t experience its first fall freeze until Nov. 2. According to Borchardt, that was just a bit behind normal.
“The first freeze, which is when the temperature drops at or below 32 degrees, typically occurs between Oct. 11 and Oct. 12 across the Chicago suburbs and Oct. 21 to Oct. 30 in the city and along the lakeshore,” he said.
The earliest first freeze on record occurred Sept. 22, 1995, at O’Hare. The latest was Nov. 24, 1931.
Winter 2021-22
It was the second-longest stretch of days between two measurable snowfalls — 287 days — but snow finally arrived in Chicago on Tuesday.
Dec. 28 also marks the latest date of a first snowfall in Chicago history going back to 1885. It was just the 26th time in the past 136 years that the city had to wait until the final month of the year to experience snow on the ground.
At O’Hare, 0.01 of an inch was recorded at 12:10 p.m. with snow still falling. March 15, 2021 was the last time more than a trace of snow was reported at the site.
“The first trace or more of snow typically occurs on Oct. 30, but has occurred as early as Sept. 25 (1942) and as late as Dec. 5 (1999),” Borchardt said. “The first measurable snow (0.1 inches or more) typically occurs around Nov. 17.”
Last year, Chicago received its first measurable snowfall of the season on Nov. 24.
“At some point, the hammer of winter will drop. Maybe it’ll be in 2022?” Borchardt wrote in an email.
What to expect this winter
The latest outlook from the National Weather Service’s Climate Prediction Center shows the La Nina climate pattern is in effect for the second consecutive year, or a “double dip,” as meteorologists call it.
As a result, the Chicago area could experience warmer weather and more rain — or not.
“La Nina falls tend to be a bit drier and warmer across the Midwest, but there is A LOT of variability between La Nina years,” Ford wrote in an email.
According to the Climate Prediction Center, warmer temperatures and wetter-than-average conditions in the Great Lakes region are expected from January through March.
Sources: Tribune reporting and archives; National Weather Service; Illinois state climatologist
