July is the warmest time of the year for many locations. Parts of the Desert Southwest reach peak summer temperatures in June. Portions of the West Coast have to wait until September to reach peak summertime warmth. Parts of the United States searing in long-lasting heat might be wondering if their hottest time of year has passed and when it will finally cool down. The average peak of summertime heat varies across the Lower 48, but for the majority of Americans, it happens in July or early August.
