November is low season. Prices may rise a bit for early December. Christmas - New Years commands the year's highest prices. January prices are more moderate. Peak season is February through March or maybe into April a bit.
Like most of the east Caribbean area, the sky is bluest in January to April/May. The sky is slightly grey in June - August. You can get a brief shower any day of the year, but there are more showers in June/August. "People" don't holiday there in September through November - the height of the hurricane season. Some hotels close in September - October.
And I think Runway31 meant 82F, not 82C
Temps, including the sea, don't change much throughout the year.