9 US National Parks Where You Can Escape the Summer Heat

Redwood National and State Parks is certainly one of the most reliably shaded national parks in America, thanks to a canopy of coastal redwoods that can reach over 300 feet (91 meters) tall. The dense tree cover, combined with cool marine fog that rolls in most mornings, keeps summer temperatures in the 60s and 70s (15–21°C) even when inland California is baking.

If you make it out there, trails such as Lady Bird Johnson Grove and Fern Canyon (no permit needed if you hike in!) stay shaded and moist most of the day.

Insider tip: Mornings are foggiest and coolest, so plan longer hikes early and save shorter strolls for the afternoon, once the mist burns off.

Tucked just south of the border to Canada, Voyageurs National Park is one of the best cool-weather national parks the US has to offer, with nearly 40 percent of its landscape made up of open water. Breezes off Rainy, Kabetogama, Namakan, and Sand Point lakes keep summer days mild, often lingering near 70°F (21°C), with cool nights that dip into sweater-weather territory.

And because the park has no interior roads, you can explore by canoe, kayak, boat tour, or houseboat, letting the water do double duty as both transportation and air conditioning.

Did you know?: Voyageurs is a certified International Dark Sky Park, so a summer stay also means some of the best stargazing in Minnesota—and the country.

For national parks to beat the heat with total certainty, head underground. Mammoth Cave, the longest known cave system in the world, holds a constant temperature of about 54°F (12°C) year-round, regardless of what's happening in the Kentucky sun outside.

Here, ranger-led tours range from an easy 0.5-mile (1-kilometer) walk past dripstone formations to a more strenuous route through the Historic Entrance.

Insider tip: The cave's steady chill means it's one of the only national park experiences where the forecast genuinely doesn't matter. Bring a light jacket and book tours in advance through the Mammoth Cave website, since summer slots sell out quickly.

Surrounded by Lake Superior—the coldest of the Great Lakes—Isle Royale National Park is proof that in US national parks, summer travel doesn't have to involve sweating. Lake Superior's cool water moderates the island's climate, keeping summer highs comfortably in the 60s and 70s (15–21°C) even in July and August.

The park is only reachable by boat (from Houghton and Copper Harbor, Michigan; and from Grand Portage, Minnesota) or by seaplane (from Hancock/Hubbell, Michigan; and from Grand Marais, Minnesota), but once you're there, moose may outnumber the humans you’ll see on the backcountry trails.

Insider tip: While many people camp, there are also cabins and a lodge on the island for a more comfortable stay. Just be sure to book in advance.

Glacier is consistently ranked in the top tier of cool US national parks in summer (in both senses of the word), thanks to elevations that climb well above 6,000 feet (1,828 meters) along the Going-to-the-Sun Road.

Even when nearby valley towns see 85°F (29°C), high alpine passes such as Logan Pass typically stay between 50°F and 60°F (11–16°C), with snowfields lingering into July. Plus, the road's opening date shifts year to year depending on Montana’s snowpack, so early-season alpine access can be limited, making summer a no-brainer.

Insider tip: Mornings at Logan Pass are especially crisp, making it a good time to spot mountain goats before afternoon crowds and warmer air move in. (And now that timed entry passes are no longer required, traveling here is even easier.)

Olympic is one of the US national parks with mild summer weather almost guaranteed, largely because it contains several distinct climates within a single boundary.

The Hoh Rainforest, one of the wettest places in the contiguous US, stays cool and green under a thick, moss-draped canopy even in August, while the nearby Washington coastline brings in marine fog and breezes. Higher elevations at Hurricane Ridge add alpine chill to the mix, too.

Did you know?: The Hoh Rainforest receives more than 140 inches (355 centimeters) of rain annually, which is exactly what keeps it so lush and cool.

If you're chasing the best national parks to escape the heat entirely, Denali's subarctic summer climate is hard to beat. Up here in Alaska, daytime highs typically hover around 60°F (16°C), occasionally reaching 71°F (22°C), while nights can dip close to freezing even in July.

Long daylight hours also mean more time to spot moose, caribou, and grizzlies along the park road, all in the shadow of North America's tallest peak.

Insider tip: The main road through the park is scheduled to open in 2027. Before then, it does mean more restricted access—but it also means smaller crowds.

Acadia is a favorite for summer travel to national parks along the East Coast, largely because the cold Atlantic keeps temperatures in check even during peak season. Coastal breezes off Maine’s Frenchman Bay typically hold highs at a comfortable 71°F (22°C), and granite peaks such as Cadillac Mountain offer a few extra degrees of relief at elevation.

Additionally, the mix of rocky shoreline, spruce forest, and carriage roads makes it easy to find a cool spot no matter the time of day.

Did you know?: Cadillac Mountain is one of the first places in the US to see sunrise for part of the year, making morning the time to be there—though expect to share the moment with your fellow park-lovers, as it’s a popular pilgrimage.

Rocky Mountain National Park in Colorado is regularly cited among the best US parks for summer escapes, thanks to Trail Ridge Road—climbing above 12,000 feet (3,657 meters), it ranks as the highest continuous paved highway in the country.

At that elevation, summer highs often stay below 70°F (21°C), even when Denver, just a couple hours away, swelters. And alpine tundra, wildflower meadows, and thin, crisp air make the drive itself one of the coolest experiences in the park system.

Insider tip: Afternoon thunderstorms are common at high elevation in summer, so plan to be off exposed ridgelines by early afternoon.