Chicago’s Friday starts partly cloudy and near 60 degrees, but showers and a few thunderstorms are expected to develop around midday and continue into the afternoon. The National Weather Service Chicago/Romeoville forecast puts the rain chance near 50%, with temperatures reaching about 68. Storms are expected to be isolated and produce light rain, easing around sunset; no watches or warnings are listed.
Friday’s showers in a wider rainfall context
The Illinois State Climatologist Office reports that northeast Illinois has become wetter over time, with much of the precipitation increase occurring in summer and fall. It also reports more heavy-rain events in recent decades. These are regional historical findings; they do not explain Friday’s forecast or establish how much rain any particular shower will bring.
A much more severe local episode illustrates why those conditions should not be confused with this forecast. The National Weather Service Chicago’s account of July 2, 2023 describes several extended rounds of heavy to torrential rain in and around Chicago, with totals generally around 3 to 7 inches and some localized amounts above 8 inches, causing flash flooding. That event differs substantially from Friday’s forecast of isolated storms and light rainfall; it is a historical example, not evidence of what will happen today.
There is also a local infrastructure limitation worth keeping separate from the forecast: the Metropolitan Water Reclamation District of Greater Chicago says neighborhood sewer capacity can affect whether water reaches the Tunnel and Reservoir Plan system. As general context, street flooding or basement backups can therefore occur even when that system has room. This is not a prediction of flooding from Friday’s expected light showers.
Breezy, warmer weekend, then more rain chances
South-southeast winds around 10 mph accompany Friday’s afternoon showers and storms. Tonight should become mostly clear after a slight chance of an early-evening shower or storm. The low is near 60, with gusts potentially reaching 20 mph.
Saturday is forecast to be partly sunny and dry, with a high near 76. South winds of 10 to 15 mph could gust to 25 mph. Sunday turns mostly sunny and cooler, with a high near 68 and light east winds; Monday is expected to rebound to about 78 under mostly sunny skies.
The forecast turns more unsettled after Monday: showers and thunderstorms could return Monday night and Tuesday, with additional rain chances Wednesday and more likely showers and storms Wednesday night into Thursday. Thursday is expected to be mostly cloudy with a high near 69, while a stronger front late in the week could bring much colder temperatures.
