They're predicting summer in the Caribbean. At this time of year storms are common, and it's hurricane season. You might have lovely (but very hot) weather, or you might have storms, or you might have something in between. You never know.
long-range forecasts are far from accurate. You would get a more accurate forecast if you checked middle of next week. For the most part its summer in the Caribbean which means hot days with the chance of a pop-up shower or thunderstorm that usually lasts about 20 minutes. Balmy nights with a beautiful sea breeze. Hurricanes don't usually start getting active until late July early August.