Chicago weather: Weather experts says winter is over. These were its warmest, coldest and snowiest days.

Chicago is under a winter storm watch, but spring has already sprung for weather experts.

That’s because experts prefer to track weather in four increments of three months each — instead of astronomical seasons, which are defined by equinoxes and solstices.

So, March 1 was the start of meteorological spring, which sticks around until the end of May.

WGN-Ch. 9 chief meteorologist Tom Skilling is frequently asked why forecasters prefer to follow meteorological seasons.

[ Tom Skilling Q&A: WGN-TV’s chief meteorologist on ‘barbaric’ cold and snowy weather from the city’s past ]

“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.

With a weakening La Nina climate system still in effect, Chicago has been warmer than average — which means snow has been scarce.

The city typically experiences about two days with a snowfall greater than 6 inches between December and February, National Weather Service meteorologist Brett Borchardt told the Tribune, but that didn’t happen at all this winter.

A daily snowfall of 1 inch or more was recorded just seven times during the 89-day season.

Though snowfall was lacking, Chicago had more rain than expected.

[ Chicago weather: How our 2022-23 seasonal snowfall compares with previous winters ]

Warmest high temperature: 59 degrees

Blizzardlike conditions hit just before Christmas, but became milder just before the new year.

The average temperature for the three-month span was 31.8 degrees, Borchardt said.

Temperatures topped out in the 50-degree range a total of 15 days during the three-month span — four in December, three in January and eight in February.

Only 19 days between December and February had high temperatures below freezing.

Coldest low temperature: Minus 8 degrees

An Arctic blast of below-zero temperatures and bitter wind chills forced the cancellation of some of the city’s much-loved holiday attractions and produced one of the coldest Bears home games.

Though temperature departures were below normal for about 10 days, that was the worst the “Hawk” thrust upon the city this winter.

Subzero temperatures were recorded just five days during meteorological winter — three of those were observed on consecutive days (Dec. 22-24).

[ What is a polar vortex? How often does the weather phenomenon happen here? Experts explain. ]

[ Chicago’s coldest recorded temperatures and longest stretches of deep freezes ]

[ Brrrrr down: A look at the coldest Chicago Bears games at Soldier Field ]

Highest daily rain accumulation: 1.38 inches

What the city lacked in snow, it gained in rain.

Borchardt said this winter was the 15th wettest on record with 8.59 inches of liquid water (melted snow and rain) recorded — that’s a bit more than 2.5 inches above normal.

Highest daily snow accumulation: 3.6 inches

The only significant thing about this winter’s snowfall was its absence.

Just 18 inches of snow fell this winter at O’Hare International Airport, the city’s official recording site — that’s roughly 20 inches below normal.

The most snow Chicago has ever received in one season is 89.7 inches during 1978-79. The least — 9.8 inches — occurred in 1920-21.

[ Chicago’s 10 largest snowfalls since 1886 — and how the Tribune covered them ]

There are equal chances for above or below normal temperatures this month, so it’s difficult to predict if we’ll be wearing shorts or snow pants.

The rise in temperatures through meteorological spring is stark with high temperatures typically in the lower 40s in early March and in the mid 70s by late May, Borchardt said.

Our mild winter has encouraged perennial plants to sprout and for animals to emerge from hibernation or migration. Any frosty conditions for an extended period of time could spell trouble for them, Illinois state climatologist Trent Ford told the Tribune.

[ Chicago weather: When to expect the last freeze and snow of spring ]

Our wet winter is expected to be followed by a wet spring, which makes it a good time to consider taking one of the National Weather Service’s severe weather spotter training sessions since thunderstorms and a potential tornado could be sparked due to unstable conditions this time of year.

Borchardt said Chicago typically sees 6 to 8 inches of snow during spring with the majority of it falling in March, so it’s not quite time to give up on sledding or snowman-building yet.

krumore@chicagotribune.com

Twitter @rumormill