Another factor in choosing a time to cruise is weather. If you wish to cruise in the Caribbean, hurricane season (officially June 1 through November 30, but more realistically late August through mid-November) can often be unpredictable. Since hurricanes can be forecasted and tracked, cruise ships are usually able to avoid them, but there may be missed ports and rough seas without warning. Cruise lines know this, and the prices for Caribbean cruises during this time reflect the unreliability of the weather and itineraries.
Weather can also play a significant part in where cruise lines will sail. Alaska and northern Europe have cool temperatures, and are generally only ‘bearable’ to cruisers in the summer months. South American and Australian cruises tend to be popular in the American winter, as it is summer in the southern hemisphere during those months. Caribbean, Mexican and Hawaiian cruises are also much more readily available during the winter months. European cruises sail from spring through the fall, but usually not during the winter.
As you can see, changing weather makes for changing itineraries, but that also leads to another interesting aspect of cruising: the repositioning cruise. If a cruise ship winters in the Caribbean, but spends its summers in Europe, then it will have to sail to Europe in the spring, and return back to Florida in the fall. These one way repositioning cruises are often the best cruising deals available. Cruise lines normally have a difficult time filling a long cruise, during school weeks, with few ports, particularly when one way airfare is taken into account (many airlines charge as much for a one way ticket as a round trip, particularly when you are talking about overseas travel). For this reason, there are many adherents of repositioning cruises: people who like the long sea days, uncrowded ships and cheap cruise fares. Yet they are not enough to completely fill the ships. If you are flexible in your schedule and can travel last minute, you will usually find many last minute specials on such cruise vacations.