With the traditional start of the rainy season.
|The graph above shows daily high and low air temperatures measured at Naples Airport compared to the long-term average and historical extremes.|
Can you see it also occurs when long-term nighttime low temperatures rise (and stay) above 70° F? Meteorologist usually use that, not Memorial Day, as the more scientific guide. Notice, too, the hotter than normal temperatures for April. That explains why the buildup of afternoon rains during that span.
Also explains why I enjoyed that cool respite in early May so much.
Once June starts those days are through.