Is the weather in south miami beach always this hot and humid during the summer months?

At nighttime me and my friend went to South Beach last summer (July 21), it was 90 degrees, 90% humidity and to top that off there was no wind "breeze". Air was still and it felt like I was in a sauna! I was staying in Fort Lauderdale where it was nice, temperature was not hot, not cool, with nice breeze and NO high humidity. During the day, the temerature/humidity was not a problem. Can anyone tell me if its always like that during the summer at night? Or we just went on a bad day?