When to go
The season is four months long and nothing sails outside it, so the question is not really “when” but “which four weeks”. Whales, daylight, bears and crowds peak at different points, and no single month wins on all of them.
Quick answer
The best time for an Alaska glacier cruise is mid-May to the first week of August, with June and July the peak. The season runs from about the middle of May to the middle of September and no day boats operate outside it. Mid-May is cheapest and quietest with snow still low on the mountains; July has the longest days and the calmest water; August brings bears and rain; the first half of September is empty and gets cancelled more.
Month by month
Four calendars overlapping: whales, daylight, bears and crowds.
Mid-May – early Jun
Snow still low on the mountains, which is the best backdrop of the whole year. Humpbacks arriving and feeding, puffins coming ashore, boats half empty and fares at their lowest. Some of the longest routes do not start until the end of May, so check the sailing you want actually runs.
Jun – Jul
Nineteen hours of daylight in June, the statistically calmest water of the year, whales feeding hard and every boat running every day. Also the busiest: the six and eight-hour sailings sell out first, so book about a week ahead.
Aug
Humpback numbers thin after the first week. Salmon run, which puts bears on the streams and makes the Anchorage wildlife days worth doing. The light turns golden earlier in the evening, and it rains more.
Sep
The first two weeks still sail, the fjords are almost empty and the colours on the tundra are extraordinary. Weather cancels more often, and by the middle of the month the fleet is out of the water for the year. Free cancellation matters most in this window.
Why the season is only four months
Storms, daylight and departing animals — in that order. Not temperature.
People assume the boats stop because it gets cold. It does get cold, but Resurrection Bay is ice-free all year and the harbour never closes. The reason the day boats stop is weather.
From late September the North Pacific storm track moves south and the Gulf of Alaska becomes one of the roughest pieces of water in the northern hemisphere. A six-hour cruise requires an hour of open-water running each way, and that stops being reasonable long before it becomes impossible.
Daylight matters too. An eight-hour sailing needs a genuinely long day at each end for boarding and the run home, and by the end of September Seward has lost five hours of daylight from its June peak.
And the animals leave. Humpbacks move south, puffins go back out to sea, and the seabird cliffs empty. By October the coastline is doing the same thing it does every winter, which is nothing anyone can sell a ticket to.
Choosing your weeks
Each of these is a real choice, not a compromise.
Lowest fares, half-empty boats, snow still on the mountains, whales arriving. The cost is that a few of the longer routes have not started yet.
Whales feeding, puffins nesting, nineteen hours of daylight and the calmest statistical water. Also the most expensive and the fullest.
The salmon run, and the Anchorage-based wildlife days are at their best. Whale numbers are falling and rain is more likely.
The light is lower and warmer, the tundra turns, and there are far fewer people on the decks. The weather is the trade.
Cancellations are commonest. If you have exactly one day and it is in September, book it early in your trip so a cancellation is not the end of it.
Unlike some regions, morning and afternoon sailings here see broadly the same things. Morning departures are the longer trips simply because they need the hours.
Free cancellation to 24 hours on every departure here is what makes booking early and watching the forecast a sensible plan rather than a gamble.
Prices and what is included→Common questions
June and July: the longest days, the calmest water and whales still feeding hard. Mid-May is cheaper and quieter with better mountain scenery, and the first half of September is almost empty but gets cancelled more often.
About the middle of May to the middle of September. No day boats operate outside that window, and a few of the longest routes do not start until the end of May.
Mid-May to July for the widest combination — whales feeding, puffins nesting and long daylight. August specifically for bears, because the salmon are running.
The first two weeks, yes, if you are flexible. The fjords are empty, the light is extraordinary and the fares are lower. Cancellations are commonest in this window, so do not make it the last day of your trip.
About a week for the six and eight-hour sailings in July, and a few days at either end of the season. Everything here cancels free to 24 hours, so booking early costs nothing.
Rain does not; the boats run through it and a low cloud on the fjord walls is its own thing. What stops a sailing is swell in the Gulf, and that is commonest at the very end of the season.
Go deeper
Fifteen departures priced per person and per hour, from $116 to $1,334.
Kenai FjordsAialik, Holgate and Northwestern — which boat reaches which face, and for how long.
VerdictFifteen departures ranked for one decision, with a straight answer at the end.
WhalesHumpbacks feed here rather than pass through — what that means for your odds.
SewardEvery sailing out of the small boat harbour, and how to get there from Anchorage.
WhittierPrince William Sound, twenty-six named glaciers, and the tunnel you have to time.
Kenai Fjords Glacier Cruise with Lunch
★ 4.9 · 921 reviews · Free cancellation 24 h