Upper air set-up—pool of unseasonably cool air positioned over the Great Lakes 

Saturday afternoon temperature anomaly—how much below normal?

It was a cool start Tuesday morning—many outlying areas began the day in the upper 40s. 

Tuesday area low temperatures 

Among the area’s coolest lows Tuesday morning

Temperatures warmed up nicely following a cool start across the Chicago area with another day of nearly totally sunny skies. Daytime highs were a few degrees higher than observed on Labor Day. 

Intense heat continues to broil the Southwest, and parts of the High Plains where a record high temperature occurred Tuesday at Rapid City, SD.  

September’s remarkably sunny start to continue on Wednesday with little or no cloud cover expected. 

Tracking the changing weather pat tern this upcoming weekend—forecast low temperatures each morning. 

The mercury is likely to dip into the lower 40s Sunday morning for areas well away from Lake Michigan. 

Wed AM 

Thu AM

Fri AM 

Saturday AM 

Sunday AM 

Monday AM 

Brief surge in temperatures Thursday afternoon before the coolest air of the season to date arrives on Saturday

Wednesday P.M.

Thursday P.M.

Friday P.M.

Saturday P.M.

Sunday P.M.

Monday P.M.

Saturday to feature an early taste of Fall—temperatures more like mid-October than early September

Central and Eastern U.S. overall is forecast to be much below normal for the next week following a brief spike on Thursday—but temperatures are expected to bounce back before the middle of the month with warmer than normal air returning. 

Forecast temperature anomaly next 7 days through September 9: 

Forecast temperature anomaly September 10 through 16:  

Source: weathermodels.com