A FREEZE WARNING has been issued for all of northern Illinois beginning late Tuesday night (Midnight), lasting through Wednesday morning, as temperatures are expected to fall into the mid and upper 20s.
A strong cold front moved through the Stateline early Monday morning bringing with it a few light rain showers. The front pushed well south of the region by the afternoon, holding temperatures in the 40s across much of northern Illinois and southern Wisconsin. While much of the afternoon was dry, a sprinkle or even light snow flurry will be possible late Monday night as an upper level disturbance moves in from Wisconsin.
Along the cold front showers have been persistent for much of the day across central Illinois, with snow showers coming down across the central Plains. As an area of low pressure moves in from the west Tuesday, snow showers will begin to expand eastward through Missouri, southern Iowa and parts of Illinois during the afternoon and evening. The greatest chance for accumulating snow appears to remain further downstate across central Illinois, Indiana and southern Michigan. There, several inches of snow will be possible. Further north, a dusting to a trace of snow may occur on grassy and elevated surfaces.
Drier air moving in Tuesday night will help push the precipitation out, but the chill will begin to set in. Despite the cloud cover, overnight lows are forecast to fall into the mid and upper 20s, ranging between 25-30 degrees. Temperatures falling to 28 degrees, or below, is considered a killing freeze and could damage any plants sensitive to the extreme cold. This means you’ll need to bring in any plants, such as hanging or potted, to protect them from the cold and cover up any plants/vegetables that may be coming up in the yard or garden. You’ll want to do this before dusk, removing the covering just after sunrise the following morning. For the farm fields, there hasn’t been much corn planted so far in northern Illinois and anything that has been planted will likely be okay with the growing stage of corn remaining below ground.