Winter Storm Warning Mammoth, Montana

Winter alerts in Mammoth, newest first, in effect or ended
Alert	State	Severity	Places
Winter Storm WatchEnded Up to 7 inches of snow possible, gusts up to 30 mph. Issued October 8 Ended October 9, 2026	Montana	Severe	75 places Mammoth Great Falls Helena Helena Valley Southeast Helena Valley West Central Helena Valley Northwest Malmstrom AFB Helena Valley Northeast Big Sky Montana City and 65 more
Winter Weather AdvisoryEnded Up to 4 inches of snow above 6500 feet. Issued June 25 Ended June 29, 2026	Montana	Moderate	19 places Mammoth Big Sky Montana City Clancy West Yellowstone Boulder South Hills Jefferson City Rader Creek Basin and 9 more
Winter Weather AdvisoryEnded 3 to 7 inches of snow, with higher amounts on high peaks, gusts up to 40 mph. Issued May 15 Ended May 18, 2026	Montana	Moderate	41 places Mammoth Bozeman Belgrade Four Corners Big Sky Montana City Manhattan Clancy King Arthur Park West Yellowstone and 31 more
Winter Storm WatchEnded 2 to 7 inches of snow possible, highest on the south and east portions of the Bozeman valley. Issued April 14 Ended April 15, 2026	Montana	Severe	16 places Mammoth Bozeman Belgrade Four Corners Big Sky Manhattan King Arthur Park West Yellowstone Churchill Gallatin Gateway and 6 more
Winter Storm WarningEnded 7 to 11 inches of snow at and below pass level with higher amounts above pass level. Issued March 31 Ended April 3, 2026	Montana	Severe	7 places Mammoth Big Sky West Yellowstone Hebgen Lake Estates Neihart Monarch Lakeview
Winter Storm WatchEnded 7 to 14 inches of snow possible at and above pass level with 3 to 7 inches at lower elevations, gusts up to 40 mph. Issued March 30 Ended March 31, 2026	Montana	Severe	76 places Mammoth Great Falls Lewistown Malmstrom AFB Big Sky Montana City Clancy Sun Prairie West Yellowstone Boulder and 66 more
Winter Storm WarningEnded 4 to 9 inches of snow below 7000 feet with 9 to 16 inches above 7000 feet, gusts up to 35 mph. Issued March 5 Ended March 5, 2026	Montana	Severe	5 places Mammoth Big Sky West Yellowstone Hebgen Lake Estates Lakeview
Winter Weather AdvisoryEnded 3 to 6 inches of snow at pass level with higher amounts above pass level, gusts up to 35 mph. Issued March 3 Ended March 5, 2026	Montana	Moderate	55 places Mammoth Bozeman Belgrade Four Corners Dillon Big Sky Montana City Manhattan Clancy King Arthur Park and 45 more
Winter Weather AdvisoryEnded 1 to 3 inches of snow. Issued February 17 Ended February 19, 2026	Montana	Moderate	115 places Mammoth Bozeman Helena Belgrade Helena Valley Southeast Helena Valley West Central Lewistown Four Corners Helena Valley Northwest Dillon and 105 more
Snow Squall WarningEnded Intense bursts of heavy snow. Issued February 17 Ended February 17, 2026	Montana	Severe	14 places Mammoth Three Forks Clancy Boulder Wheatland Jefferson City McAllister Willow Creek Pony Harrison and 4 more
Snow Squall WarningEnded Intense bursts of heavy snow. Issued February 17 Ended February 17, 2026	Montana	Severe	10 places Mammoth Boulder Whitehall Sheridan Rader Creek Twin Bridges Basin Alder Silver Star Brandon
Winter Weather AdvisoryEnded 2 to 6 inches of snow, with up to 10 inches at mountain peaks. Issued February 15 Ended February 17, 2026	Montana	Moderate	146 places Mammoth Great Falls Havre Helena Valley West Central Malmstrom AFB Big Sky Shelby Cut Bank Montana City North Browning and 136 more
Winter Weather AdvisoryEnded 3 to 5 inches of snow, near 12 inches of snow at ridge tops. Issued February 8 Ended February 9, 2026	Montana	Moderate	67 places Mammoth Helena Helena Valley Southeast Lewistown Helena Valley Northwest Helena Valley Northeast Big Sky Montana City East Helena Clancy and 57 more
Winter Weather AdvisoryEnded 1 to 3 inches of snow at lower elevations and up to 6 inches in the mountains south of West Yellowstone, gusts up to 45 mph. Issued January 5 Ended January 6, 2026	Montana	Moderate	5 places Mammoth Big Sky West Yellowstone Hebgen Lake Estates Lakeview
Winter Weather AdvisoryEnded Up to 6 inches of snow, gusts up to 55 mph, 1 to 3 inches of snow, gusts up to 45 mph. Issued December 26 Ended December 27, 2025	Montana	Moderate	5 places Mammoth Big Sky West Yellowstone Hebgen Lake Estates Lakeview
Winter Weather AdvisoryEnded Up to 6 inches of snow near pass level, gusts up to 55 mph. Issued December 25 Ended December 27, 2025	Montana	Moderate	8 places Mammoth Big Sky West Yellowstone East Glacier Park Village Babb Hebgen Lake Estates St. Mary Lakeview
Winter Weather AdvisoryEnded 1 to 4 inches of snow over the valleys and 4 to 10 inches at and above pass level, up to a glaze of ice, gusts up to 40 mph. Issued December 21 Ended December 22, 2025	Montana	Moderate	109 places Mammoth Bozeman Helena Belgrade Havre Helena Valley Southeast Four Corners Helena Valley Northwest Dillon Helena Valley Northeast and 99 more
Winter Weather AdvisoryEnded Up to 6 inches of snow, gusts up to 75 mph. Issued December 16 Ended December 17, 2025	Montana	Moderate	63 places Mammoth Havre Lewistown Big Sky Fort Belknap Agency West Yellowstone Chinook Hays Harlem Havre North and 53 more
Winter Weather AdvisoryEnded 2 to 5 inches of snow, gusts up to 40 mph. Issued November 30 Ended December 3, 2025	Montana	Moderate	98 places Mammoth Great Falls Helena Helena Valley Southeast Helena Valley West Central Lewistown Helena Valley Northwest Malmstrom AFB Helena Valley Northeast Big Sky and 88 more
Winter Weather AdvisoryEnded 1 to 2 inches of snow at lower elevations, and 3 to 6 inches in the mountains. Issued October 26 Ended October 27, 2025	Montana	Moderate	47 places Mammoth Bozeman Belgrade Four Corners Dillon Big Sky Manhattan Three Forks King Arthur Park West Yellowstone and 37 more