After only two 90° days this year (94° on June 25, and 93° on June 24), and a very cool July, we should see a significant change this weekend. Ninety-degree weather will return to the area, along with muggy conditions.
We are still running behind last year's levels, and WAY below 2007's hot summer. By this point in 2007, we had achieved a total of 18 days with 90° or hotter. That summer would see 6 more 90° days by the end of the season.