We normally go in February.
It was a lot hotter and humid in July but not unbearably so, we had a fantastic time.
Line times were fine provided you got to the parks 30 minutes before opening and went on the quieter days. For the first couple of hours they were walk ons, or had waits of 10-20 minutes. After 11 the crowds built up but by then we had done all we wanted to do in the park and used Fast Passes for water rides which are extremely popular. I was expecting huge lines but there were no different to when I had been in February.