• View from Sourdough Mountain Overlook  A view looking down onto Diablo Lake. Photo Credit: NPS/Michael Silverman, 2010.

    North Cascades

    National Park Washington

There are park alerts in effect.
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  • State Route 20 closed at Mile Post 134, Ross Dam

    After a brief closure at Newhalem due to an avalanche and unstable conditions, SR 20 has re-opened to its normal winter closure point at MP 134, Ross Dam. The highway will remain closed from Ross Dam to MP 171 (Silver Star Creek) until spring re-opening. More »

  • Ross Dam Haul Road Closure Continues

    A short segment of the Ross Dam Haul Road between the Diablo Lake suspension bridge and the tunnel remains closed to public use due to continued recovery following a March 2010 landslide. The closure will remain in effect through 2014. More »

  • Notice of planned work for the Cascade River Road, fall 2014

    Visitors planning to access the park via the Cascade River Road after Labor Day should be advised that the Park Service is planning a fall closure of this road at Eldorado Creek (3 miles before the end of the road) in order to perform permanent repairs. More »

Weather

Weather in the North Cascades varies greatly depending season and location. From autumn to spring much of the park is buried under a thick layer of snow. The most accommodating weather is from mid-June to late-September, when all but the highest trails are generally clear of snow. The west slopes and high peaks catch the brunt of wet systems blowing in from the Pacific Ocean creating a more lush and temperate evergreen forest, while the shielded lower east slopes tend to be warm and dry throughout the summer.

The difference between west and east is so great that the western slopes receive an average of 76 more inches of precipitation and 407 more inches of snowfall annually. So much snow falls in the mountains that State Route 20—the only road that traverses the park from east to west—is closed every winter for four or more months. During an average year heavy snow and continuous avalanches bury the highway beyond Ross Lake Trailhead from mid-November to April. Only once (1976-77) in its more than 30-year history has the route remained open through the entire winter. No matter what time of year, visitors entering the North Cascades should remember that mountain weather is unpredictable and prone to sudden changes. Even in the summer storms are common. Especially those visitors who plan and traveling into the backcountry should be prepared for adverse conditions. Warm, waterproof clothing is all but required year-round ... just in case.

Did You Know?

lupine is a common flower in dry sunny areas

In addition to Wilderness, Recreation Areas and National Park designations there are also five Research Natural Areas in the complex: Silver Lake, Pyramid Lake, Boston Glacier, Stetattle Creek and Big Beaver Valley.