Yes -- that is correct -- the summers are getting cooler. It is obvious to those who look at data. Just go to the "Florida Climate Center" and look at the trend of "maximum" temperatures. But that's just in Florida. It can also be seen at the national level just by looking at archived data stored by NOAA -- all located at Asheville, NC -- where I used to coordinate with while in the Air Force. For those who don't have the time to download, plot, and analyze the data, here is a short video of what you'll find ...
https://www.youtube.com/watch?v=hs-K_tadveI