Chicago weather: 90-degree heat returns once more before fall begins

Chicago is gearing up for what might be the last 90-degree day of the year. 

The record temperature for Sept. 21 in the Chicago area is 94 degrees. Today's high will be closer to 92. 

Fall officially starts tomorrow and so does the drop to 70-degree days. 

Sunday will bring rain and temperatures in the mid-70s. Monday and Tuesday will also have a chance of rain, bringing some much-needed rainfall to the area.