Glacier Bay National Park weather in May

May in Glacier Bay National Park: cold, soaked, with clean air — fine if you can take 17 rainy days.

Updated September 2026 · climate normals from ERA5 reanalysis

Glacier Bay National Park🇺🇸 United States · Alaska & the Far North · National park68
  1. 29Jan
  2. 38Feb
  3. 45Mar
  4. 56Apr
  5. 68May
  6. 79Jun
  7. 82Jul
  8. 72Aug
  9. 61Sep
  10. 50Oct
  11. 34Nov
  12. 26Dec

#4 of 12 months in Glacier Bay National Park · #1053 of 1413 destinations to visit in May · comfort 68/100 (tier C)

Days
5°C
Nights
2°C
Wet days
17
Sun
9.7 h
Humidity
84%
Daylight
17 h
Glacier Bay National Park, United States
Photo: Beth Fitzpatrick · Pexels

Traveller notes on Glacier Bay National Park in May

Other months in Glacier Bay National Park

Glacier Bay-forum threads comparing May against June call June the somewhat busier but equally strong pick, both sitting among the driest stretch of the year before conditions turn noticeably wetter by September and October. Posters are direct even a genuinely warm June day here rarely climbs much past the 50s Fahrenheit, real layers essential regardless of how the forecast looks from the mainland. Large cruise ships run through daily starting mid-May, only two permitted in park waters on a given day and limited to a brief window, so posters recommend an early breakfast, sometimes as early as 6:30am, to claim a good viewing spot before the crowd builds. Regulars call a warmer-than-usual June a genuine bonus for dramatic glacial calving views. The record: 8.3C days feeling like 6C, 4.5C nights, an extraordinarily high 158mm across over 15 days, a notably high 21.5cm of fresh accumulation and 88 percent humidity.
GlacierBayJuneRegular · June · 1 month ago · Read more on Tripadvisor ↗
Glacier Bay-forum threads on cruise timing describe August as generally reliable weather-wise, though posters are consistent cruisers should simply expect rain as the default and treat sunshine as a pleasant bonus rather than an assumption. An earlier week in the month is a reasonable bet for slightly milder conditions than the tail end of August. The real risk is described as wind coming directly off the glacier itself, capable of making the deck genuinely uncomfortable even when the rest of the day feels mild, so posters recommend packing layers regardless of the general forecast. Late August into early September is named a genuine sweet spot for a secondary reason beyond glaciers - bears actively fishing for salmon, early fall color starting, and virtually no mosquitoes left by that point. The record: 10.4C days feeling like 9C, 6.7C nights, an extraordinarily high 343mm across over 17 days, a 14.5C sea and 89 percent humidity.
GlacierBayAugustRegular · August · 1 month ago · Read more on Tripadvisor ↗
Glacier Bay's forum is almost entirely spring-and-summer boat tour talk, with essentially nothing about January - a telling gap, since the cruise season that most visitors experience the park through runs roughly May to September and simply doesn't operate in the depths of winter. The park's own climate record explains the silence: daylight shrinks to about seven hours, temperatures sit well below freezing, and heavy, sustained snowfall piles up through the month. This is a summer-boat-tour destination in practice, not a place with a real winter visitor season to ask forum questions about.
SoutheastAlaskaRegular · January · 1 month ago · Read more on Tripadvisor ↗
Forum posters visiting Glacier Bay in July describe conditions as definitely cold despite it being the height of summer, with wildlife - eagles, otters and seals - reported all over the place and the glaciers and scenery themselves the clear highlight of the visit, including the sound of the ice actively calving. Posters generally recommend real layers and rain gear for a July visit here, since conditions on the water can shift quickly and stay genuinely chilly even in midsummer. Posters consistently rate the wildlife viewing and glacier scenery as worth the cold-weather preparation, framing July as prime wildlife season here even though the temperatures themselves stay far from what summer implies elsewhere.
Tripadvisor community · July · 1 month ago · Read more on Tripadvisor ↗

Add your own note from Glacier Bay National Park's card on the map.

Glacier Bay National Park climate normals — May

Daytime high5°C / 41°F🧥 cold
Nighttime low2°C / 35°F
Feels like (high)3°C / 37°F
Sea temperature7°C / 45°F🥶 cold sea
Rainfall297 mm / 11.7 in⛈ soaked
Rainy days17 days
Humidity84%💦 very humid
Dew point1°C / 33°F
Sunshine9.7 h/day
Daylight16.9 h
Wind12 km/h / 8 mph
Snowfall119.8 cm / 47.2 in
Air quality (US AQI)37🍃 good

Monthly averages from ERA5 reanalysis. AQI is the mean US Air Quality Index for the month.

Crowds in Glacier Bay National Park in May

How busy the place itself is — school and mass holidays, the months an editor tagged, and how sought-after the weather makes them. Never part of the comfort score.

BusyCruise ship season(estimated)

JFMAMJJASOND

Peak crowdsBusyShoulder seasonQuiet

Best months for Glacier Bay National Park's weather

Ranked by this destination's own climate comfort score across the year — a different thing from how busy it gets (see Crowds above).

Fair weatherGlacier Bay National Park's weather peaks June–August, best around July.

JFMAMJJASOND

Best weatherFair weatherToughest weather

What's on in Glacier Bay National Park in May

Recurring seasonal events, natural spectacles, closures and holidays — curated and sourced.

  • Season

    Cruise ship season

    15 May – 15 Sep · usuallyCruise seasonCrowded

    Up to two large cruise ships a day spend most of a day in the bay through the summer, with park rangers boarding to narrate; kayakers and day-boat passengers share the tidewater glaciers with them. Source ↗

  • Opening

    Summer visitor season

    20 May – 10 Sep · usuallySummer season opensBook early

    Late May to early September is when the lodge, the day boat up the bay, the kayak rentals and the ranger programmes at Bartlett Cove all run, with July the peak. Book the boat and the kayaks before you book the flight into Gustavus. Source ↗

  • Season

    Winter shutdown

    20 Sep – 15 MayOff-season shutdownClosures

    Once the season ends the lodge, the tour boat and most of Gustavus close, and the park is a handful of residents and a lot of weather. Nothing stops you visiting; almost nothing is running when you get there. Source ↗

  • Season

    Snow season

    Ski season

    About 120 cm of snow falls in the month.

    from the climate normals

What's on around the world in May →

Nearby, and something's on

Within 300 km of Glacier Bay National Park — a day trip or a short hop — with something on this month. Never part of the comfort score.

Where is Glacier Bay National Park?

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Glacier Bay National Park in May — FAQ

Is May a good time to visit Glacier Bay National Park?
May in Glacier Bay National Park: cold, soaked, with clean air — fine if you can take 17 rainy days. It ranks #4 of 12 months for Glacier Bay National Park on SeasonMap's comfort score (68/100).
What is the weather like in Glacier Bay National Park in May?
In May, Glacier Bay National Park averages a daily high of 5.1°C and a low of 1.6°C, with about 296.6 mm of rain over roughly 16.8 rainy days.
What is the air quality in Glacier Bay National Park in May?
Glacier Bay National Park has a mean US Air Quality Index of about 37 in May.
Does it snow in Glacier Bay National Park in May?
Glacier Bay National Park sees roughly 119.8 cm of snowfall in May.

Within 300 km: Juneau's Humpback whale season around 1 May – 20 Sep.