I love July through Sept. I live on Caye Caulker and love the water. Nov to April it can be windy, water is choppy..our windsurfing and kite boarding residents come then...but the nights are cool and that I do love. July thru Sept the water is usually like glass..perhaps a bit too warm but still the reef is so kool..the manatees come out here that time of year and its not unusual too run into one. The rain has never seemed an issue to me, but the nights are hot so make sure you have A.C. in the last 50 years Belize has been hit by hurricanes only in late Sept and October,,,that means nothing really with all the running around and prep we went thru early in the season for Dean and Felix....On the mainland you may find it more uncomfortable, too humid. Nothing is really for sure...it can rain during dry season, not rain during rainy season,,,weather patterns are changing..just come when you can, this little country has alot to offer............
You should be aware the weather reports you read will say its raining when it isnt..somtimes..I dont know whats up with that,,but we are always talking to friends in the States that say,,oh I see youve been having some rain..WHAT RAIN, NO RAIN....only sunshine....