Sunshine is the most common forecast in the Caribbean, but the lush vegetation found on many Caribbean islands attests to the fact that it does sometimes rain, as well. For up-to-the-minute weather information for your Caribbean travels—including alerts on hurricanes and tropical storms—check out regional and international weather resources.
The U.S. National Weather Center's National Hurricane Center is the single best information site on the Internet for information on the tropical storms and hurricanes that occasionally affect the Caribbean during the Atlantic hurricane season, which runs from June 1 to November 30. The Center provides highly accurate satellite storm tracking from the coast of Africa to the Gulf of Mexico and issues storm watches and warnings that travelers should pay careful attention to as their vacation date draws near.
If you want to get firsthand reports on the damage (or lack thereof) caused by major storms in the Caribbean, this is the place to go. The Caribbean Hurricane Network features reports and commentaries from amateur and professional meteorologists and weather-watchers on islands across the Caribbean.
The Weather Channel's site provides excellent long-range, daily, and hour-by-hour weather information on most Caribbean destinations.
The ironically named Weather Underground includes weather information from around the world, including a comprehensive tropical-weather section.
The Caribbean Disaster Emergency Management Agency (CDEMA) features weather forecasts for Anguilla, Antigua and Barbuda, the Bahamas, Barbados, Belize, the British Virgin Islands, Dominica, Grenada, Jamaica, Montserrat, St. Kitts and Nevis, St. Lucia, St. Vincent and the Grenadines, Trinidad and Tobago, and Turks and Caicos.
Bermuda is actually located in the South Atlantic Ocean, not the Caribbean Sea, so it's important to get island-specific weather information before you travel to Bermuda. The Bermuda Weather Service provides a marine forecast, hourly weather reports, weather imagery, historical data, and more.
The Bahamas are closer to the Caribbean Sea than Bermuda and more tropical in character but are still far enough north to share many weather characteristics with south Florida. Again, a specific forecast is in order if traveling to the Bahamas, and this government agency provides a wealth of information (in addition to a boast that the Bahamas enjoys more than 315 sunny days annually).
The weather doesn't vary too much from island to island in the Florida Keys, but this site nonetheless provides historical weather information on the main Keys plus tide predictions and current weather conditions.
Curacao is located off the coast of Venezuela and is subject to the constant trade winds. Unlike most Caribbean destinations, Curacao is a desert, not a tropical island. This site offers comprehensive weather information on Curacao.
Jamaica is one of a handful of Caribbean destinations that is large enough and has enough topographic diversity that localized weather reports become meaningful. Go Jamaica provides current weather information on Falmouth, Kingston, Montego Bay, Ocho Rios, Port Royal, and more.
Getting accurate information into or out of Cuba isn't always easy, but this website does provide a daily weather forecast and information on Cuban climate and average temperatures in cities across the Caribbean's largest island.