Usually, I post re my travels, but I am running behind so this is purely informational. The cruise lines won't post it but..by destination here's the skivy.
CARIBBEAN-Best in December-April. Worst is August-October because of hurricane season
MEXICAN RIVERA-Year round but very hot in August-September. Hurricane season May 15-November
MEDITERRANEAN: Best in June or September (August is the most crowded). Worst is December-February. Season runs April-October but is becoming year round.
NORTHERN EUROPE-Season runs May-September. Best is June-August. Worst in early May
ALASKA-Season runs May-September with the best being July and August. Worst is May or September.
NEW ENGLAND-Season runs April-October. Best July-October. Worst is April and May.
TRANS-ATLANTIC- Season March-November. Watch for repositioning cruises (meaning deals) in Spring and Fall. Best is June-August. Worst is March or November. The Queen Mary 2 was built just to cross the Atlantic.
ANTARCTICA-Season Nov-March. Best mid-December-February Worst is Nov or March. It is the one destination where weather can be tricky even in high season as crossing the Drake Passage is historically a very treacherous stretch of water.
Hopefully this was beneficial to you. Bon Voyage!!!