Some might say that Alaska is beautiful even if the weather is not, but the reality is as the summer progresses it gets increasingly wet in the Inside Passage. And since most cruisers to that part of the world see an Alaska sailing as a once-in-a-lifetime trip, unless the cruise is out of reach to you financially, we suggest sailing in the dryer months of May and June. And Alaska isn't the only major cruise destination with a rainy season to avoid: Both Hawaii and the Mediterranean have "wet" times of year, which can come with — in addition to low fares — rough seas.

Summer is a particularly popular time for families to cruise the Caribbean, so after the kids go back to school the rates drop significantly. But the Caribbean's hurricane season extends all the way through November. If you jump on a low fall fare, you should be prepared for occasional rough seas and possible schedule disruptions which can range from cancelled snorkeling excursions and rained out beach days all the way to skipped ports. The good news: Since ships can usually outrun storms and change their course if necessary, we're talking inconvenience rather than danger.

Holiday cruises have a double whammy on the mainstream lines: They are often among the most expensive sailings of the year and they're also the cruises with the largest volume of children on board. Plus, if you think by cruising you're getting away from, say, Christmas, you're wrong: Cruise ships celebrate Christmas big time, including visits by Santa, special holiday menus, and even caroling. If you're a bah humbug type, these cruises aren't the solution to avoiding the traditional sights and sounds of the holiday season.

Spring brings attractive pricing in the Mediterranean and Baltic, and it's a great time to take an ocean cruise in Europe. But flooding can make passage through the locks on the major European rivers, including the Rhine and Danube, impossible. Conversely, late summer can bring low waters, particularly on the Elbe River. That doesn't mean that your cruise will be cancelled: The river lines have contingency plans that involve buses and moving guests between ships.

Looking for peace, quiet, and sunshine? If you're not traveling with kids, we suggest avoiding cruises during the February and March school vacation periods. There are often a lot of kids on board, from partying college types (especially on less expensive, shorter sailings) to families with multiple children who are taking advantage of school vacations. Even if you have extra time off from work during this time, and the weather and rates look good, your only chance at a quiet sailing is picking a ship with age requirements, such as those by Viking Ocean Cruises and Windstar Cruises.