The week started out with temperatures in the 70s and sunny skies, but things are about to get downright frigid in the Chicago area, as a freeze warning has been issued for most of northern Illinois and northwestern Indiana.
The warning was issued by the National Weather Service, and will take effect 1 a.m. Friday. It will remain in effect through 8 a.m.
McHenry, Lake, DeKalb, DuPage, Kane, LaSalle, Kendall, Grundy, Will and Kankakee counties are all impacted by the warning, as are northern and southern Cook County. Lake, Porter, LaPorte, Newton and Jasper counties in Indiana are also included.
Parts of Chicago may not see temperatures drop below freezing, according to the alert.
A freeze warning is issued by the National Weather Service when low temperatures are expected to drop below the freezing mark, and that is exactly what will happen overnight Thursday and into Friday, with lows in the upper-20s and low-30s across the area.
Temperatures that low can kill crops and other sensitive vegetation, and could cause damage to unprotected outdoor plumbing fixtures, according to NWS officials.
Residents with plants should take steps to protect them, and should also wrap, drain or slowly drip outdoor plumbing fixtures to protect them from freezing.
Local
Most of the Chicago area has already seen its first sub-freezing low temperature of the season, according to the National Weather Service. Most areas saw those readings earlier this month, just ahead of their normal first freeze, which typically occurs in northern Illinois between Oct. 11 and 20th.
The city of Chicago has not yet seen its first freeze, with warm air from Lake Michigan and the urban heat island helping to keep temperatures above freezing.
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Some parts of the city could potentially see sub-freezing temperatures overnight, according to forecast models.
