Temperatures Saturday and Sunday soared into the low to mid 90s across northern Illinois and southern Wisconsin, with a peak heat index Sunday afternoon well over 100 degrees. Thunderstorms Sunday evening did bring temperatures down, but didn’t do much to get rid of the humidity. In fact, it remained rather muggy through late Monday morning. That’s when a cold front came through, bringing down a drier air mass.
A couple cold fronts passing through the Midwest this week will keep temperatures right at, or just slightly below, normal. Tuesday will likely be our ‘warmer’ day with temperatures in the mid 80s. You may also notice just a slight uptick in the humidity late Tuesday and Wednesday, ahead of a second cold front that’ll pass Wednesday afternoon.
The heat from the weekend has pushed south and west as winds in the jet stream shift to the northwest. The northwest flow will continue to feed a drier and less moisture rich air mass into the Great Lakes. Weak disturbances moving through the northwest flow will bring at least an isolated chance for showers and storms late Tuesday, Wednesday and Thursday, but with moisture lacking the risk for any significant storm system will be reduced.