The National Weather Service has issued an Excessive Heat Warning for the City of St. Louis along with St. Louis county and Phelps and Dent counties in Missouri through Tuesday and has issued a heat advisory for much of the rest of the area into Tuesday.
In the City of St. Louis, the heat index may top 110 by Monday and Tuesday afternoon. Excessive heat over several days can be dangerous, especially in urban areas.
Some relief can be expected by Wednesday with the chance for thunderstorms increasing.