HAWAII
Best months: March to July, October and November
Not so good: Far from horrible, December and January are coolest (average afternoon temperature is 75 degrees); August and September are hottest (average 92 degrees). The wettest months are from November to March.
Note: In general, every island's northern shore gets more rain than the southern, especially on Kauai and the Big Island.
BAHAMAS
Best months: November to April
No so good: It is hottest (up to 89 degrees on average) and rainiest from June to October
BERMUDA
Best months: May to October
Not so good: January and February
CARIBBEAN
Best months: Technically, December to May, when the area is coolest and enjoys the most wind, but average temperatures year-round hover between 78 and 88 degrees
Not so good: "Official" hurricane season runs from June to November; the worst months are August, September, and October (islands near South American -- Aruba, Bonaire, Curacao, Trinidad, and Tobago -- are outside the hurricane danger zone)
EUROPE
Best months: April through October or November
Not so good: December to March
Mexico
Best months: October to May
Not so good: Rainy season runs June through September, but usually only involves a short daily dousing. It is also hotter during the summer months.
SOUTH PACIFIC (Fiji, French Polynesia)
Best months: May to October
Not so good: December to February ( hot, humid, and rain); Tahiti lies well outside the Pacific cyclone zone and while Fiji does not, it is rarely hit during the highest-risk months of January and February.