Mean average water temperature here varies from 76 degrees in February, to 84 degrees in September. In between those months, water temp is between those temps.
Corals find it hard to survive unless temp is between 75 and 85 degrees. In 1998, average temp in september was 86 to 87 degrees, and we had loads of coral 'bleaching', which coral does when under stress. Bleaching is where the coral turns white.
These very warm sea temps resulted in Hurricane Mitch, which was a monster!!!!
Please note the above are average temps, you will find warmer and cooler spots.