Sunday forecast: Staying warm and humid in Chicagoland, showers and storms skewing north

After a Saturday scorcher marked one of the hottest days of the year, we’re in for another warm and humid day around Chicagoland on Sunday.

In may not get quite as sultry as Saturday, but high temperatures are projected to reach the upper 80s, with heat index values getting to about 90 or 95.

On-and-off showers and storms are also possible, but the main threat for rain will be in areas to the north and northwest, where soaking rains moved in Saturday and have caused flooding over saturated soil.

A Flood Watch is in effect for Lake and McHenry counties until 10 a.m. Sunday, while counties just over the border in southern Wisconsin are under a Flood Watch through Monday morning. As for Chicagoland, rainfall is likely to be more widespread on Monday than it is on Sunday.

While cooler, less humid air is bringing some relief to areas west of Chicagoland, it’s not likely to reach our area until around Tuesday. That will bring a nice midweek cooldown, but not for long, because more heat and humidity are in the forecast by next weekend (see more below).

Beach forecast

It’ll be a great day to beat the heat Sunday at Chicagoland’s Lake Michigan beaches.

The water temperature has climbed to the upper 70s in Chicago, now warmer than it was all of last year.

Daylight decreasing

Saturday night was the last night of sunsets at or after 8 p.m. for the rest of the year.

Looking ahead, temperatures will dip to the seasonal low to mid-80s from Monday through Wednesday, though muggy air and afternoon showers or storms remain likely.

By next weekend, highs climb back into the low to mid-90s, as the dog days of late summer continue to bring heat and humidity to Chicagoland.

Total precipitation through Wednesday evening

Gargantuan rainfall totals are possible across northern Missouri, eastern Iowa and western Illinois, as a stationary front brings repeat rounds of thunderstorms. 

Across the Chicago area, current modeling suggests 1 to 2 inches may be possible, but locally heavier in some areas due to thunderstorms.  

6-10-day temperature outlook

Another round of hot weather is possible later next week, according to the latest suite of computer models. The Midwest and Northeast have a high likelihood of seeing above to potentially much above normal temperatures during the Aug. 14-18 period.