The next couple of days could make you sorry you put off getting that new battery for the car.
But even if you find yourself needing the jumper cables, remember that the Chicago area still had lead a charmed life so far this winter. Temperatures easily could be much colder, and we could have gotten a lot more snow by this time of the year.
The most frigid air mass the region has seen in two years has descended over the area. The National Weather Service said temperatures will be mostly in the single digits until Wednesday, and the low Monday night was expected to flirt with subzero levels.
With the weather as cold as it is supposed to be, the Elgin police station, 151 Douglas Ave., is serving as the primary temporary warming shelter for those who need a place to stay during such potentially dangerous conditions.
Police Commander Glenn Theriault said that the city typically never gets more than a handful of people using the station to stay out of harsh weather.
To help keep those numbers low, police have started an effort with local nonprofits, Theriault said, putting those who come in from the cold or heat in touch with agencies to get the aid they might need to stay out of such harm's way in the future.
That work has already found assistance for some of those typically seen when it gets very cold or very hot. In one case, that meant a nonprofit helping a man find a way back to Georgia, Theriault said.
Richard Castro, meteorologist at the weather service's office in Romeoville, said we'd be looking at a low of around minus 20 if the region had snow on the ground.
"This is actually quite an impressive mass of cold air," he said. Within the system, temperatures aloft are actually colder than those in the last subzero front that visited Chicago in February 2011.
Castro said the earlier system produced a minus 9 reading at O'Hare Airport on Feb. 10, 2011, the last below-zero reading for the region. It occurred just after that winter's "Snowmageddon" with about 20 inches on the ground.
Lack of snow acts as insulation. Castro said that if the incoming weather produces below-zero temperatures, it will mark a rarity for Chicago.
A weather service study of the period from 1960 to 2010 found only 16 days with no snow cover and temperatures in the negative range, Castro said.
Wind chills were a big concern, with Monday night probably marking the worst of it.
Castro said wind chills could reach 20 below in the city Monday night and 25 below in areas further from Lake Michigan.
The weather service expects temperatures to slowly moderate later in the week, with a chance of snow Thursday. Depending on the track of that storm, it could break Chicago's ongoing record for most days without at least an inch of snow, Castro said.
As of Monday, the Chicago area has recorded 332 days without a snowfall of at least an inch and 330 days without a snow depth of at least an inch, he said. Both streaks broke records set in 1940, Castro added.
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