The peak tourist season is between December and April, but this has more to do with the climate in North America than anything else. During these months the island is swamped by visitors, prices are highest and accommodation can be hard to find. Obviously it’s much less crowded during the official hurricane season (May through November). Although hurricanes are rare, they’re able to do more than merely put a dampener on your holiday. Definitely keep an eye on weather reports if you’re in Puerto Rico at this time, especially in August, September and October. If you intend to travel inland bring a sweater for the evenings regardless of when you visit – it’s much cooler in them thar hills.
Weather – Puerto Rico is balmy year round, with daily highs averaging between 27-30°C (80-86°F). Hurricane season is between May and November, especially intense in the months of August, September and October. Otherwise rain is fairly regular throughout the year, with February and March being slightly drier than other months.