Going-to-the-Sun Road
Choose a few viewpoints along the mountain drive and check that year’s vehicle-entry and shuttle rules. Early snow can interrupt higher sections in September.
September · mountain road · check access
What to see and do in Glacier in September
Choose a mountain drive, a lake stop or a substantial hike. Check snow on the higher trails separately.
Grinnell Glacier area
A substantial high-country hike with colder mornings and possible early snow. Check the trail report and leave room to choose a lower outing.
September · Grinnell Glacier area
Lake McDonald
A lower-valley option if early snow changes a mountain outing. Pack layers for a cool lakeshore start or finish.
September · Lake McDonald
Glacier weather in September
September’s normal high is 68°F and low is 41°F, with 1.96 inches of precipitation. The W Glacier station sits near the West Entrance at about 3,148 ft, in the valley where the plowed winter road starts. The east side (St. Mary, Many Glacier, Two Medicine) and Logan Pass, at 6,646 ft, are higher, so expect colder weather there. Treat these numbers as a west-side valley guide; high-country hikes need a mountain forecast.
Cooler Hotter
Jan
High30°F
Low19°F
Precip · in3.54
Feb
High34°F
Low19°F
Precip · in2.17
Mar
High43°F
Low25°F
Precip · in2.58
Apr
High53°F
Low31°F
Precip · in2.15
May
High64°F
Low39°F
Precip · in2.62
Jun
High70°F
Low45°F
Precip · in3.80
Jul
High80°F
Low50°F
Precip · in1.39
Aug
High79°F
Low48°F
Precip · in1.17
Sep
High68°F
Low41°F
Precip · in1.96
Oct
High52°F
Low33°F
Precip · in3.05
Nov
High37°F
Low26°F
Precip · in3.23
Dec
High29°F
Low20°F
Precip · in3.21
Glacier crowds in September
September averages 557,269 recreation visits, 73% of the peak monthly average in July.
LowestLowModerateHighPeakAverage month: 254,484September
Tips for your September visit
Set the road plan before choosing the hike.
AWest EntranceBSt. Mary EntranceCMany Glacier EntranceDTwo Medicine EntranceEPolebridge Entrance (North Fork)
- Park boundary
Going-to-the-Sun Road access
Confirm the full-road opening and that year’s entry and shuttle rules. Lower-valley access does not establish access to Logan Pass or snow-free higher trails.
How we built this page.
An independent guide using official data. Not affiliated with or endorsed by the National Park Service.
- Crowds
- 2021–2025 monthly averages. NPS recreation visits, compared with the park’s own busiest month. Visits are not unique visitors or a count of people on a trail.
- Weather
- 1991-2020 climate normals. NOAA’s W Glacier, MT station. These describe typical weather at the station, not every part of the park or a forecast.
- Roads & lodging
- Normal seasonal schedules. NPS guidance and official operator information. Confirm access, hours and availability before you travel.
Historical records and data-quality checks
- Visit history: 1979–2025 NPS monthly recreation visits.
- Weather history: 1949–2025 daily observations, separate from climate normals. We average daily highs and lows and total the rain for each month.
- Complete months only: every day must pass our quality checks for that metric. Missing or incomplete records stay blank; we never interpolate.
- Excluded measurements: flagged, presumed-zero and lagged values. Trace rain counts as zero measurable rainfall.