Actually, the difference in the sun strength is very minimal from 30 to 40 n during the summer solstice. The bigger difference is in winter, its a bigger jump in strength from a 30-degree sun angle to a 40-degree sun angle than it is from an 83-degree sun angle to a 73-degree angle. Despite Miami having a sun angle 10 degrees higher than ours year-round, the difference in summer strength is only marginally so whereas on the winter solstice their angle is 30 % stronger than ours. I think people notice the oppressive humidity which makes them feel like its stronger.