I was there last October and will be going back again this October. Last year the first 8 days or so were fabulous, a few afternoons of clouds, very few showers, no real rain. After that I moved into Guatemala for a few days and by the time I'd made it back into San Ignacio, Hurricane Wilma was passing by the Cayes. I missed that, but heard there was a bit more bad weather around the Cayes (but not a direct hit or anything) because of it... mostly just higher winds, waves, etc... As long as the hurricanes stay away the weather is amazing.