Glacier National Park weather in September

September in Glacier National Park: cool, a little rain, with clean air — an excellent time to visit.

#3 of 12 months in Glacier National Park · #165 of 604 destinations to visit in September · comfort 86/100 (tier A)

Updated June 2026 · climate normals from ERA5 reanalysis

Glacier National Park climate normals — September

Daytime high16°C / 60°F🙂 cool
Nighttime low6°C / 42°F
Feels like (high)12°C / 54°F
Rainfall52 mm / 2 in🌦 some rain
Rainy days9 days
Humidity63%💧 humid
Dew point3°C / 37°F
Sunshine10 h/day
Daylight12.6 h
Wind15 km/h / 9 mph
Snowfall8.7 cm / 3.4 in
Air quality (US AQI)37🍃 good

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

Where is Glacier National Park?

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Glacier National Park in September — FAQ

Is September a good time to visit Glacier National Park?
September in Glacier National Park: cool, a little rain, with clean air — an excellent time to visit. It ranks #3 of 12 months for Glacier National Park on SeasonMap's comfort score (86/100).
What is the weather like in Glacier National Park in September?
In September, Glacier National Park averages a daily high of 15.5°C and a low of 5.7°C, with about 52 mm of rain over roughly 9.4 rainy days.
What is the air quality in Glacier National Park in September?
Glacier National Park has a mean US Air Quality Index of about 37 in September.
Does it snow in Glacier National Park in September?
Glacier National Park sees roughly 8.7 cm of snowfall in September.

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