Over the Caribbean during December winds tend to be mostly from the east or northeast averaging forces 4-5 (11-21 knots), except the eastern Caribbean where the wind tends to averaging force 4 (11-16 knots). Over the Gulf of Mexico winds tend to be more variable but still averaging mostly forces 4-5 (11-21 knots). The risk for gale force or higher winds is low, generally 1 % or less, except for the westernmost Gulf of Mexico where the gale risk is 2-3%.
Over the Caribbean waves generally average 3-7 feet, however, the risk of encountering rough 8 foot or higher seas is about 10% over the Gulf of Mexico and ranges from 10 to 30 percent over the central and western Caribbean with the highest risk concentrated north of the Colombian coast. The eastern Caribbean tends to average 2-5 ft waves and the risk for rough seas of 8 ft or more occur less than 10% of the time.
Air temperatures during December average 27-28 C (80-83 F) across the Caribbean, 16C-22C (61-72 F) over the northern and western Gulf of Mexico and 22-25 C (72-77 F) across the Bay of Campeche and southern Gulf of Mexico.
Most destinations in the Caribbean experience afternoon high temperatures 27-31 C (80-88F) with late night and early morning lows 21-25 C (70-77 F) It will be somewhat cooler in the northern Bahamas where afternoon highs tend to be around 25-26 C (77-79 F) and lows 20-21 C (68-70 F)
Sea surface temperatures range from 26-28C (79-82 F) in the Caribbean, 18-24C (64-75 F) over the northern and western Gulf of Mexico and 24-27C (75-81 F) in the Bay of Campeche and southeastern Gulf of Mexico.
Wettest destinations are the Virgin Islands, Puerto Rico, Martinique and St Lucia where you can expect 15-20 days with some rainfall while driest destinations include the Bahamas, Cuba, and Jamaica where rain falls on 10 days or less.
Tropical cyclone activity is rare this month.