The NWS in Indianapolis has issued a Heat Advisory through Wednesday evening for the entire forecast area. Already today, the temperature is up to 87 degrees at noon with a heat index of 95. Hopefully we'll hit 95 today with a heat index of at least 107. The purple areas of the map indicate an Excessive Heat Warning. I imagine these areas were placed under the warning because they are heavily populated with a lot of concrete and automobiles which creates the "heat island" effect.