It wasn't measurable, but the first snowflakes hit the suburbs. Here's when the real stuff comes.

Though the suburbs saw an early glimpse of snow Monday, the area's first official snowfall of the season could still be a month out.

Meteorologists say the first measurable snowfall typically arrives in mid-November.

The median first date of measurable snowfall — snow that visually reaches at least a tenth of an inch — for the Chicago region is somewhere from Nov. 11 to Nov. 20, according to the Midwest Regional Climate Center. In some suburbs, that window is even later.

“Once you get south of I-80, you start getting toward late November, and by central Illinois you're at early December,” said Matt Friedlein, a meteorologist with the National Weather Service's Romeoville office.

Friedlein said more specific dates are available for Chicago and Rockford, where the National Weather Service has two long-term climate sites.

Chicago's normal measurable snow date is Nov. 18, “normal” referring to the median date over a 30-year period.

While the earliest recorded measurable snow blanketed Chicago on Oct. 12, 2006, the region's latest first snow was recorded just last year, on Dec. 28.

Monday's snow, recorded by the National Weather Service at its O'Hare site, was not measurable but was officially recorded as the region's first traceable snow at 9:21 a.m. The service's Rockford weather station soon followed, notching its first observed snow around 1 p.m.

Data shows Chicago's earliest occurrence of a first snow sighting was recorded Sept. 25, 1928, and the latest was Dec. 5, 1999.

Looking ahead, the National Weather Service is planning to release a winter outlook for December, January and February later this week — though meteorologists say how much snow we'll get this winter is “impossible” to predict.

“That will just give you signs of whether or not it will be warmer or colder than normal, and wetter or dryer than normal — and how much likelihood,” Friedlein said. “It won't give you specific numbers necessarily. That's impossible to do, unfortunately, but it gives some idea.”

Though long-range weather forecasts are limited in accuracy, a snowier, wetter winter could be in the cards for the Chicago region.

According to the most recent seasonal outlook from the National Weather Service's Climate Prediction Center, Illinois could see more precipitation than normal, along with a wide swath of the Midwest, including Indiana and much of Ohio.

Meanwhile, temperatures in the region are predicted to remain near average levels.

• Jenny Whidden is a Report For America corps member covering climate change and the environment for the Daily Herald. To help support her work, click here to make a tax-deductible donation.