Montana's calendar is set by its high roads, not the calendar on the wall. Going-to-the-Sun Road in Glacier usually opens all the way only in late June, the Beartooth Highway runs from about Memorial Day to mid-October, and most of Yellowstone's roads close to cars at the start of November. Pick your month by deciding which of those you need.
Roughly: July and August are the only months when everything is open at once, and also the busiest and most likely to be smoky. June and September are the best value if you can live with a few closures. December to March belongs to skiers and to snowmobile and snowcoach trips into Yellowstone. Dates below are for 2026 and the 2026/27 winter unless marked as typical.
Montana's seasons at a glance
- Peak summer (July to August): all park roads open; the Logan Pass shuttle and three-hour parking limit at Logan Pass ran July 1 to September 7 in 2026. Highest prices and crowds.
- Early summer (late May to June): Yellowstone fully open by late May, but Glacier's high road is usually still being plowed. Rivers run high with snowmelt.
- Autumn (September to mid-October): quieter parks, elk rut, fall colour in the valleys. High roads close from mid-October.
- Late autumn and spring (November, April): the "mud seasons". Ski areas are not yet open or have closed, and most Yellowstone roads are shut.
- Winter (December to March): skiing at Big Sky, Whitefish Mountain, Bridger Bowl and others; guided oversnow travel in Yellowstone from December 15.
Month by month
| Month | Roads and parks | Events and activities | Watch for |
|---|---|---|---|
| January | Yellowstone open only to snowmobiles and snowcoaches, except the North to Northeast Entrance road | Skiing; snowmobiling from West Yellowstone and Cooke City | Arctic cold snaps, especially east of the Divide |
| February | As January | Whitefish Winter Carnival, first weekend of February | Wind and drifting snow on the plains |
| March | Yellowstone oversnow season ends March 7 to 15, 2027, by road | Spring skiing | Road closures between seasons |
| April | Yellowstone's West Entrance to Old Faithful and Mammoth to Norris roads opened April 17, 2026 | Ski areas close for the season | Snow at elevation, closed side roads |
| May | Yellowstone East (May 1) and South (May 8) entrances open; Dunraven Pass and the Beartooth Highway opened May 22, 2026 | Miles City Bucking Horse Sale (held every May since 1951); Pompeys Pillar opens May 1 | Late snowstorms; high, cold rivers |
| June | Going-to-the-Sun Road opened fully June 22, 2026 | Little Bighorn anniversary, June 25 to 26 | Snow still closes some Logan Pass trails |
| July | Logan Pass shuttle and three-hour parking from July 1 | Montana State Fair, Great Falls (July 24 to August 1, 2026) | Peak crowds; start of the smoke season |
| August | Everything open | Crow Fair at Crow Agency (August 14 to 16, 2026, for visitors) | Wildfire smoke; full campgrounds |
| September | Logan Pass shuttle ends on Labor Day (September 7, 2026); Pompeys Pillar and the Lewis and Clark Caverns tours close September 30 | Dillon's Jaycee Labor Day Rodeo; elk rut | Early snow at high elevations |
| October | Beartooth Highway closed October 9, 2026; Yellowstone's West, East and South entrance roads closed October 31, 2026 | Fall fishing; quiet trails | Sudden storms on high roads |
| November | Glacier's winter entrance rates from November 1; Yellowstone closed to cars except North to Northeast | Ski areas begin opening late in the month | Shoulder-season closures in gateway towns |
| December | Yellowstone oversnow season opens December 15, 2026 | Ski season in full swing | Short days: about 8.5 hours of daylight at midwinter |
Glacier: when Going-to-the-Sun Road opens
There is no set opening date for the full Going-to-the-Sun Road. Plowing crews work from both ends toward Logan Pass (6,646 ft), and the National Park Service says the average full opening since 2010 has been around June 26. In 2026 it opened on June 22. The full road normally stays open until the third Monday of October, but weather can close it earlier: in 2026 a storm closed the alpine section on October 9.
- Lower sections, such as West Glacier to Lake McDonald, stay open in winter as far as Lake McDonald Lodge.
- In 2026 there were no vehicle reservations anywhere in Glacier. Instead, the ticketed Logan Pass shuttle and a three-hour parking limit at Logan Pass ran from July 1 to September 7.
- Vehicles longer than 21 feet or wider than 8 feet may not drive between Avalanche Creek and Rising Sun.
- If you want Logan Pass trails free of snow, aim for mid-July onwards. On the day the road opened in 2026, the Highline Trail was still closed by snow.
When the high road is shut, US-2 over Marias Pass links West Glacier and the east side all year.
Yellowstone road seasons on the Montana side
Three of Yellowstone's five entrances are in Montana: North at Gardiner, West at West Yellowstone and Northeast near Cooke City.
- North to Northeast Entrance (via Mammoth and the Lamar Valley): the only park road open to ordinary cars all year. In winter it dead-ends at Cooke City because the Beartooth Highway beyond is closed.
- West Entrance: open to cars mid-April to October 31 (2026 dates: April 17 to October 31). From December 15, 2026 to March 15, 2027 it is open only to guided snowmobile and snowcoach trips.
- Beartooth Highway (US-212) and Dunraven Pass: typically from the Friday of Memorial Day weekend to mid-October. The planned 2026 closing was October 12; the Beartooth actually closed on October 9 because of weather.
Ski season
Most Montana ski areas open between late November and mid-December, depending on snow, and close between late March and mid-April. Opening dates for 2026/27 were not announced for the big resorts when this was checked, so look at each resort's site before booking. Bozeman's Baxter Hotel flashes a blue beacon when Bridger Bowl gets 2 inches or more of new snow. Big Sky Resort has 5,850 acres and a 4,350-foot vertical drop.
Shoulder seasons: what you gain and lose
Late May and June: Yellowstone is fully open from late May, wildlife is with young, and prices are lower than in July. The trade-off is Glacier: until the Sun Road opens you can drive only the lower ends, though valleys such as Many Glacier and the shores of Lake McDonald are usually reachable.
September and early October: the best month for many visitors. Crowds thin after Labor Day, the Logan Pass shuttle stops, and the high roads stay open until mid-October in a normal year. Some state park sites switch to shorter hours from mid-September, and many seasonal sites close on September 30.
November and April: cheap but limited. Many gateway-town businesses close, most park roads are shut and ski lifts are not running.
Wildfire smoke season
Smoke is the wild card of a Montana summer. It comes from fires in Montana and also from Idaho, Washington, Oregon, California and Canada, and it can arrive with little warning. Late July through September is the usual risk window, but Canadian smoke pushed some north-central Montana monitors to "Unhealthy" in June 2025, and in late July 2026 much of western Montana was near or above an AQI of 100 under a 21-county air quality alert. Check the Montana DEQ's forecasts at todaysair.mtdeq.us and keep a flexible day or two in your plan.
Before you go
- Check Glacier's road status at nps.gov/glac or 406-888-7800, and Yellowstone's at 307-344-2117.
- Check state highways on MDT's 511 map (511mt.net) before crossing passes in spring and autumn.
- In July and August, book the Logan Pass shuttle on Recreation.gov 60 days ahead or at 7 p.m. MDT the night before.
- Look up AQI the morning of any big hike.
- If you're coming for skiing, confirm opening day on the resort's own site.
Details checked October 2026.