Yes the past few days there has been a lot of rain which will affect the visability slighlty mainly in the first 10 ft or so of water since fresh water is less dense than salt therefore stays on the surface.
it should clear up in a few days,
Water temp here is a steady 80 degrees with slight fluctuations, visability can vary from 40-120ft depending on the site and weather at the time but expect a good 80ft on most dives.
have a great time when you visit i am sure you will love exotic caye and the diving.
Gaz Cooper's DIVE BELIZE www.divebelize.com