Six of the last seven days the temperatures at Chicago's Midway airport reached at least 90 degrees. On Tuesday, Chicago’s O’Hare airport reached 92 degrees, the hottest temperature there so far this year.
Other notable temperatures on Tuesday included a record high of 98 degrees in Miami.
For Wednesday, a heat advisory was issued for parts of the Southeast where the heat index – or what it feels like -- could approach 110 degrees.
The Fourth of July is forecast to be similarly scorching, with humidity creating conditions that feel like at least 100 degrees from the Plains and Gulf Coast all the way to the East Coast.
In addition to the heat, storms with heavy rain are a possibility for several regions.
Parts of the Plains and East Coast could see more than three inches of rain that could cause localized flooding over the holiday weekend.