Personally, if it were me, I would choose somewhere other than the Caymans. How about Aruba? Aruba is warm year-round, with NO hurricane season. Pick the Cayman Islands during Spring Break.
I pulled this info from Caribbean Magazine --
Cayman Islands Weather and Climate Overview:
Average yearly temperature is 79° F. Average rainfall is 60 inches mostly in the rainy season, May through October. Blessed with cooling tradewinds, the Cayman Islands enjoy a temperate climate year-round. The hottest months are July and August when average temperatures top out at 85 to 90°; the coolest month is February, when highs range from 72 to 86° and nighttime lows dip to the mid-60s to lower 70s. Water temperatures drop during the winter months, ranging from 78 to 82°. During the summer, the waters warm to 82-86°, a balmy bath-like temperature that makes wetsuits strictly optional. The best diving conditions are in the summer (warmest water, best visibility and calmest seas). No matter when you go, a light sweater may be needed in the evenings, or a waterproof windbreaker for boat trips. Rainfall varies with the season, reaching its peak during hurricane season. Average rainfall is 46 inches annually; May and October (and September-November) are traditionally the wettest months. The driest times are March and April. Mention weather and the Caribbean in the same sentence and, quite predictably, the topic of hurricanes arises. These deadly storms are officially a threat from June through November, although the greatest danger is during the later months, basically August through October. (September is the worst.) Hurricanes are defined as revolving storms with wind speeds of 75 mph or greater. These counter-clockwise storms begin as waves off the west coast of Africa and work their way across the Atlantic, some eventually gaining strength and becoming tropical depressions (under 40 mph) or tropical storms (40-74 mph). Excellent warning systems keep islands posted on the possibility of oncoming storms. Radio Cayman (105.3 and 89.9) broadcasts current storm reports in the islands. Given that mid-December to mid-April (winter) is the peak tourist season, when rates are substantially higher and beaches and lodgings more crowded, it's best to go in the summer. There is more rain in summer, but it tends to come in downpours that clear as quickly as they arrive. Nervous Nellies will tell you that this is hurricane season, but the chances that you'll get swept up in the big one are slim. Even so, it's best to keep an eye on the weather reports in the days before your arrival.
tj