At first it seemed difficult to believe. Was the National Weather Service really issuing a winter storm warning for snowfall in late June?
But this really happened. Three US states have been hit by winter storm warnings and Yellowstone National Park is experiencing snowfall. This has left many people wondering why and what caused this unusual phenomenon. What’s even stranger is that the summer snowfall warning was coming when the eastern half of the US was experiencing record-breaking heat and the heat index was even predicted to reach 115 degrees in some places.
according to USA TodayThe weather alert “covered parts of Idaho, Montana and Wyoming – especially at higher elevations along their shared border.” As far as Yellowstone, “Snow and rain showers. A slight chance of thunderstorms this afternoon. Up to 6 inches of snow accumulation.” read the forecast For June 29, this confirms that the claims of snowfall in June are real.
A ‘deep under-level trough’ is causing ‘unseasonably cold air masses’ to cause winter storm snowfall.
according to USA Today, The storm is being operated by “A deep trough Drowning, dragging across the Rockies and the Intermountain West an unseasonably cold air mass Due to this, the temperature in some areas is falling 15 to 20 degrees below normal.”
Snow viewing areas included Yellowstone National Park, According to Fox Weather.
“Rare winter storm warnings and winter weather advisories remain in effect during snowfall in late June, even in places Yellowstone National Park,” Fox reported. “Snow fell at western mountain resorts in June, surprising skiers and spectators,” powder.com Informed. “Resorts such as Brighton, Alta, Big Sky and Timberline reported brief snowfall over the summer.”
Is snowfall unusual? After all, mountain passes are at high altitude. Yes. This has happened before, but it’s rare, Fox Weather reported, “Montana typically sees only one winter storm warning in the month of June, while Idaho has only seen two such alerts since 2020.”
idaho state journal It also wrote that the snowfall was unusual, “Eastern Idaho is flipping from summer to winter and back again – temperatures so dramatic that a rare winter storm warning has been put on the books and some local towns are well within striking distance of decades-old cold records.”
The newspaper further stated that the National Weather Service “has issued a Winter Storm Warning for the end of June – covering the backcountry area of Lemhi County above 6,500 feet. This warning, in effect Saturday evening through Monday morning, calls for 4 to 8 inches of heavy wet snowfall in Lemhi County, with up to a foot of snow on the highest peaks due to westerly winds gusting up to 30 mph. Can.” forecast had turned into rain By early June 29th.
The newspaper added: “Although mountain snowfall in late June is not so unusual in eastern Idaho, winter storm warnings are a very rare occurrence.”
But was snow really predicted in June?
(Photo by Mario Tama/Getty Images)
Yes, the NWS alert mentions snowfall.
The National Weather Service office in Great Falls, Montana, reported on June 29, 2026, “Heavy wet snow. Up to 4 inches of additional snow accumulated,” adding, “Wet snow could down trees and block access to forest trails.” That alert was for northwest Beaverhead County, including the cities of Wisdom, Wise River, Dewey, Big Hole Pass and Chief Joseph Pass.
On June 27, the NWS reported, “Heavy wet snow is expected above 6500 feet. Total accumulations will be 4 to 8 inches, with the highest peaks receiving up to 12 inches.” This snowfall was predicted to continue until the morning of 29 June.
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