Tuesday forecast: Plenty of sunshine, warm temps in Chicagoland on last day of September

The summery September weather in Chicagoland rolls on for the last day of the month.

Abundant sunshine is in store for Tuesday, with high temperatures reaching the low 80s inland. A northeast breeze gusting to around 15 miles per hour later Tuesday will keep highs in the mid-70s along the lake, will some cloud coverage approaching Chicagoland toward the evening.  

That means all locations will be above the normal high of 70 for Sept. 30.

Conditions will be just about perfect for Game 1 of the NL Wild Card series between the Cubs and San Diego Padres, with first pitch at Wrigley Field scheduled for 2:08 p.m. Tuesday.

And while the calendar turns to October on Wednesday, the warm weather isn’t going anywhere. Temps are projected to remain above average for at least the next seven days, with weekend highs perhaps approaching 90 in some locations (see more below).

High pressure

A center of high pressure will sit to the north of Toronto, Canada, bringing east to northeast winds off Lake Michigan on Tuesday, keeping temps cooler near Lake Michigan.

Tuesday hourly forecast (Centered on O’Hare International Airport)

Tuesday sunburn forecast

Despite the late season and lower sun angle, it will only take about 34 minutes during peak time at 1 p.m. to get a sunburn without proper protection, according to dermatologist Dr. Bryan Schultz. 

October will begin on an unseasonably warm, summerlike note. 

Chicago forecast highs and departure from normal

Modest cooling is forecast by midweek, mainly due to easterly winds off Lake Michigan. But that will give way to another period of unseasonable warmth beginning Friday into the weekend.  

Chicago humidity forecast

Dry air cools off efficiently at night but also heats up rapidly during the day. This will also play a huge roll in the unusually warm weather that arrives later this week.  

Forecast mean maximum temperature anomaly: Oct. 2-6

Stunning daytime temperature anomalies this weekend into early next week, with highs averaging some 15-20 degrees above normal across a large portion of the Upper Midwest and Great Lakes. 

6-10-day temperature: Oct. 5-9

Above normal warmth is expected to continue for the eastern two-thirds of the U.S. through at least the opening nine days of October.  

Forecast total rainfall through Monday, Oct. 6

No rainfall is in the forecast for Tuesday, which means Chicago will finish with the seventh-driest September on record.

We’ve seen only four days of measurable rain and one day of a trace of rain this month, for a total of 0.49 inches. That’s 2.7 inches below the normal total of 3.19 inches at O’Hare for September.

No improvement for drought conditions is coming, as another full week with no rain is expected across the Chicago area and a large portion of the Midwest and Ohio Valley.

The next chance for rain in our area doesn’t arrive likely until next week Monday into Tuesday. 

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