Glacier National Park weather in May
May in Glacier National Park: cold, rainy, with clean air — a great time to visit.
Updated September 2026 · climate normals from ERA5 reanalysis
#5 of 12 months in Glacier National Park · #851 of 1413 destinations to visit in May · comfort 77/100 (tier B)
- Days
- 11°C
- Nights
- 1°C
- Wet days
- 13
- Sun
- 11.8 h
- Humidity
- 71%
- Daylight
- 15 h

Traveller notes on Glacier National Park in May
Notes from nearby Whitefish (50 km away)
Glacier National Park doesn't have its own notes for May yet — these are about Whitefish, close enough to share the season.
Whitefish-forum threads on a May visit describe road conditions into nearby Glacier National Park as the real question mark, posters planning long weekends around Memorial Day still asking about closures and access. Regulars call mid-May trips genuinely workable for Whitefish itself even when Glacier's higher routes stay closed, the town considered worth the visit on its own merits. Posters recommend checking Going-to-the-Sun Road's current status directly before building a trip around it, May opening dates here varying considerably by year and snowpack. Regulars call comparing May against September a real question worth asking, both shoulder months offering different tradeoffs on crowds and access. Posters recommend real layers regardless of a mild-looking forecast, May conditions here still capable of a genuine chill especially near the lake. The record: 19C days feeling like 19C, 3.8C nights, an extraordinarily high 53.5mm across over 9 days and 58 percent humidity.
Other months in Glacier National Park
Glacier National Park-forum threads on an April visit call this genuinely early for a real trip, posters describing Going-to-the-Sun Road as closed most of its length with park hotels and concessions not yet open. Regulars call plowing typically starting around April 1, progress often limited even by the end of the month depending on the winter's snowfall. Posters recommend Lake McDonald and a handful of lower-elevation trails as real options for anyone visiting anyway, though snowshoe rentals are worth checking given how much cover can remain. Regulars call late April into May a genuine gray area, conditions here depending heavily on snowpack and avalanche risk rather than the calendar alone. Posters recommend contacting the park directly for current road status before finalizing any April plans, conditions changing considerably from year to year. The record: 6.2C days feeling like 4C, -4.4C nights, an extraordinarily high 120.3mm across nearly 16 days and 68 percent humidity.
Glacier-forum threads on an October visit describe the target for Going-to-the-Sun Road as keeping it open to around the third weekend of October, posters calling the east side toward Logan Pass often the last stretch to close. Regulars call the west side, from Apgar up to Logan Pass, sometimes shutting as early as October 1st for utility and road work rather than weather. Posters describe the crew as generally clearing and holding the published closing date unless a genuinely major snowfall forces an early call. Regulars recommend checking the park's road status before planning a route, conditions shifting fast once the season turns. Posters call real cold-weather layers essential regardless of forecast, mornings and evenings both turning properly wintry by mid-month. Regulars call the park still genuinely stunning in October, fall color and thinner crowds both real upsides. The record: 6.1C days feeling like 2C, -2.2C nights, 140.6mm across over 14 days and 78 percent humidity.
Glacier-forum threads on typical June weather describe this as genuinely the wettest month of the year, though posters call the back half of June noticeably drier, conditions trending more settled by month's end. Regulars are direct real accumulation remains likely at higher passes throughout June, some trails still buried. Posters describe the Going-to-the-Sun Road as typically opening by late June, though a heavy winter can push that later depending on clearing crews. Regulars call the trail to Grinnell Glacier generally not opening until after the first week of July, June visitors needing to plan around lower routes. Posters recommend real flexibility built into any itinerary given how uncertain conditions run this early. Regulars call daytime highs in the sixties Fahrenheit typical, evenings cooling considerably. The record: 15.1C days feeling like 13C, 4C nights, a high 130mm across nearly 13 days, a notably high 4.9cm of fresh accumulation and 66 percent humidity.
Glacier-forum threads on September weather call it close to ideal for hiking, mild days and cool nights that regulars name a local favorite stretch, thinner crowds once school resumes and wildlife actively foraging ahead of winter making sightings more likely along the roads and trails. Posters describe occasional snow at higher elevations as entirely possible, usually melting off again within a day, heavier accumulation rare but not impossible toward the back half of the month. Layering is standard practice regardless of the forecast, a hoodie or flannel over a t-shirt with a compact shell packed for a passing shower. Wildflowers are largely past peak by September, but posters call the early fall color a fair trade, starting to show on the higher slopes. Regulars call mid-September one of the best-value weeks of the season. The record: 14.1C days feeling like 11C, 3.8C nights, 78mm across 9.7 days, a notably high 6.3cm of fresh snowfall and 65 percent humidity.
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Glacier National Park climate normals — May
Monthly averages from ERA5 reanalysis. AQI is the mean US Air Quality Index for the month.
Crowds in Glacier 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.
Shoulder seasonan ordinary month(estimated)
Peak crowdsBusyShoulder seasonQuiet
Best months for Glacier 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 National Park's weather peaks July–September.
Best weatherFair weatherToughest weather
What's on in Glacier National Park in May
Recurring seasonal events, natural spectacles, closures and holidays — curated and sourced.
- Closure
Winter closure
20 Oct – 15 MayLodges shut, the alpine road is gated at Lake McDonald and Rising Sun, and access is skis, snowshoes or the Amtrak stop at West Glacier. It is a park you have to work for, and almost nobody does. Source ↗
Nearby, and something's on
Within 300 km of Glacier National Park — a day trip or a short hop — with something on this month. Never part of the comfort score.
Where is Glacier National Park?
Glacier National Park in May — FAQ
- Is May a good time to visit Glacier National Park?
- May in Glacier National Park: cold, rainy, with clean air — a great time to visit. It ranks #5 of 12 months for Glacier National Park on SeasonMap's comfort score (77/100).
- What is the weather like in Glacier National Park in May?
- In May, Glacier National Park averages a daily high of 11.4°C and a low of 1°C, with about 117.1 mm of rain over roughly 13.1 rainy days.
- What is the air quality in Glacier National Park in May?
- Glacier National Park has a mean US Air Quality Index of about 50 in May.
- Does it snow in Glacier National Park in May?
- Glacier National Park sees roughly 26 cm of snowfall in May.
Within 300 km: Calgary's Rockies ski season around 10 Nov – 15 May.