If you guys want to know the answer just look at FL's numbers. For all intended purposes our summer weather has started. It is 90 degrees(minus this small cold front) for the past week and we will be in the 80-90s for awhile. Sun intensity is almost at summer levels according to my solar collection.
It does seem we are having lower amount of cases than expected compared to the northern states. Remember we are # 3 in population and that temperature sensing map has pinned FL to be screwed like NY for the past 2 weeks. Our hospital from Central FL released their projections and is trending lower than expected. We just had our state wide shelter in place order activated, perhaps one of the last ones.
I would believe it's the high intensity UV from the sun, not the temperature. If you believe the coronavirus jumped from bats, then those coronavirus can handle high temps in the range of 150F (bats' body temp while flying).