If you're not a fan of large crowds of children, it's best to avoid sailing from late June to August or during school holidays (late December, early January and until March). Alaska has a relatively short cruise season, and many travelers book their Alaska itineraries up to a year in advance. This means there are fewer cabins and options available for last-minute bookings. The warmer months are the most popular, so if you want to sail during June or July, plan to book your Alaska cruise six months to one year ahead of time.
Although it's possible to get lucky and find a good deal a few weeks before boarding, waiting until late spring will likely mean you miss out on the entire summer season. Plus, if you want to combine an adventure in Yukon or Denali, such as Holland America's Land+Sea Journey, you'll need some extra time to plan. Experts recommend these 10 interior upgrades. As mentioned earlier, there's no “bad time” to browse.
However, if we had to choose, we suggest April or October if you need to fly to a cruise port. Good weather and low prices make it an affordable and convenient time to travel. For these reasons, September is the worst month of the year to travel by cruise ship. April and May are great times to travel because they are out of hurricane season, although some Caribbean destinations receive more rainfall than normal in May.