I usually visit in September. School’s back in service (pre-Covid), snowbirds haven’t migrated and it’s hurricane season. Get there between hurricanes and see how empty the tourist places are. No lines in restaurants. The water is still warm enough to dip in. less traffic. Life is good then.
I visit regularly as well.
In September it was dead last year - true.
April through August in Miami is nuts. Orlando YMMV.