Rare June Winter Storm Warning Targets Western States Before July 4th

A rare June Winter Storm Warning has been issued for parts of Idaho, Montana, and Wyoming, with up to 16 inches of heavy wet snow expected to hit mountain regions just days before Independence Day. The National Weather Service (NWS) warns that the unseasonable storm threatens travelers, campers, and tourists heading to major national parks during the busiest week of the summer.

What is the National Weather Service warning about?

The NWS issued a Winter Storm Warning this weekend, cautioning residents and visitors about significant snowfall and dangerous conditions in higher elevations. Some locations could see up to 16 inches of snow, while many areas are expected to receive 4 to 8 inches. Wind gusts of up to 30 miles per hour will make conditions even more hazardous.

Plan for winter-like conditions in the backcountry and higher elevations. Cold temperatures, wind, and wet snow will elevate the risk of hypothermia. Heavy wet snow may down trees, blocking access to backcountry roadways.

The advisory highlights the real danger of wet, heavy snow snapping tree limbs and blocking remote roads, a serious concern for anyone venturing into the backcountry during what is normally peak camping season.

How rare is a June winter storm warning?

A Winter Storm Warning in late June is highly unusual, even for mountainous western states. According to the Fox Forecast Center, Idaho has only seen two June Winter Storm Warnings since 2020. Data from Iowa State University's Iowa Environmental Mesonet shows this is just the seventh June since 2005 to feature a Winter Storm Watch in Montana.

The storm is especially jarring given that valley temperatures in Montana and Idaho were sitting comfortably in the 80s and 90s just days ago. A slow-moving cold system has now pushed temperatures down by 20 to 30 degrees in those same areas, a stark reminder that Mother Nature does not follow the calendar.

Which national parks are affected by the June snowstorm?

The timing could hardly be worse for American families planning Fourth of July trips to some of the country's most popular national parks. The storm is bearing down on regions near three iconic destinations at the absolute peak of tourist season.

• Yellowstone National Park: A Winter Weather Advisory covers U.S. 20 over Targhee Pass, the main route to the busy West Yellowstone entrance. Accumulating snow will likely slow already heavy summer traffic to a crawl.
• Glacier National Park: The famous Going-to-the-Sun Road just opened for the full summer season last week after its annual snow-clearing process. Now, heavy winter weather is expected to slam the road just days after it welcomed summer travelers.
• Grand Teton National Park: While not taking a direct hit, mountain roads feeding into the park are expected to see hazardous conditions, creating potential delays for visitors.

For Iowans who have saved up vacation time and planned summer road trips to these western landmarks, the storm presents a frustrating and potentially dangerous obstacle during a cherished American holiday.

What should travelers do to stay safe?

The NWS is urging caution for anyone considering travel in the affected regions. The agency recommends delaying backcountry and high-elevation travel if possible, and being fully prepared for winter conditions if the trip cannot be postponed.

Persons should consider delaying travel across the backcountry and higher elevations. If travel is absolutely necessary, consider taking a winter storm kit along with you, including such items as tire chains, booster cables, flashlight, shovel, blankets and extra clothing. Also take water, a first aid kit, and anything else that would help you survive in case you become stranded.

Campers should also take heed. The NWS warned that even a few inches of wet snow can collapse tents and damage recreational gear, turning a fun holiday outing into a survival situation quickly.

Could this rare storm affect Iowa weather patterns?

While the winter storm is centered over the Rocky Mountain region, Iowans are no strangers to unpredictable weather shifts tied to systems moving across the country. Though no direct impact is expected in the Hawkeye State, the unusual cold front serves as a good reminder to stay prepared for rapidly changing summer conditions, whether at home or on the road.

Is it safe to travel to Yellowstone or Glacier National Park this week?

Travelers should exercise significant caution. The NWS has explicitly warned that heavy wet snow, strong winds, and sudden temperature drops make high-elevation travel dangerous. If you must travel, carry a full winter storm kit including tire chains, blankets, water, and a first aid kit. Campers should be aware that even a few inches of snow can damage tents and gear.