Pacific Northwest — Olympic + Mt Rainier + North Cascades + Mt Hood
Pacific Northwest: cool summer (60-75°F daytime), low humidity, abundant NPS + USFS camping. Top destinations: Olympic NP (rainforest + ocean + alpine), Mt Rainier NP (alpine meadows + glaciers), North Cascades NP (mountain wilderness), Mt Hood NF (camping + day trips), Crater Lake NP.
Reservation systems: Recreation.gov 6 months ahead for NPS units. Olympic NP Hoh Rainforest + Kalaloch + Mora campgrounds are gold-standard summer destinations.
- Olympic NP: rainforest + ocean + alpine, multiple campgrounds
- Mt Rainier NP: alpine meadows, Cougar Rock + Ohanapecosh campgrounds
- North Cascades NP: mountain wilderness, Newhalem Creek campground
- Mt Hood NF: USFS dispersed + developed sites
- Crater Lake NP: 6,178 ft elevation, deep blue lake, Mazama Campground
Mountain West — Colorado + Wyoming + Montana high-elevation
Mountain West summer: 6,000-9,000 ft elevation campgrounds offer 60-75°F daytime even when valley floors hit 95°F. Top destinations: Rocky Mountain NP (Estes Park CO), Yellowstone NP (multiple campgrounds 7,000-8,500 ft), Grand Teton NP, Glacier NP, Bighorn NF (WY), Beartooth NF (MT).
Booking: Recreation.gov 6 months ahead. Yellowstone Madison + Grant Village + Bridge Bay are gold-standard. Rocky Mountain Moraine + Aspenglen are family-friendly.
Great Lakes — Sleeping Bear + Pictured Rocks + Apostle Islands
Great Lakes summer: 70-80°F daytime, lake-cooled nights at 55-65°F. Top destinations: Sleeping Bear Dunes National Lakeshore MI (D.H. Day + Platte River campgrounds), Pictured Rocks National Lakeshore MI (Twelvemile Beach + Hurricane River), Apostle Islands National Lakeshore WI (Quarry Bay + Stockton Island), Isle Royale NP MI (backcountry, boat-in only).
Booking: Recreation.gov 6 months ahead. Sleeping Bear D.H. Day fills fastest; book at 6-month opening.
Northern New England — Maine + New Hampshire + Vermont
Northern New England summer: 70-80°F daytime, 50-60°F nighttime. Top destinations: Acadia NP ME (Blackwoods + Seawall + Schoodic campgrounds), White Mountain NF NH (Crawford Notch + Bartlett campgrounds), Green Mountain NF VT (Hapgood Pond + Greendale campgrounds), Baxter State Park ME (Mt Katahdin).
Booking: Recreation.gov 6 months ahead for NPS. Maine State Parks (Camden Hills, Lily Bay, Mt Blue) reserve via Maine Bureau of Parks system.
Alaska — the ultimate cool-summer destination
Alaska summer (June-August): 60-75°F daytime, 20+ hours of daylight in north Alaska. Worth the long drive (Alcan) or ferry (Marine Highway). Top destinations: Denali NP, Kenai Fjords NP, Wrangell-St Elias NP (largest US NPS unit), Glacier Bay NP.
See dedicated Alaska RV wiki article for ferry-vs-Alcan + bear safety details.
Avoid — destinations to skip in summer 2026
Summer destinations that get unbearably hot: Arizona (Phoenix area 110°F+), Death Valley NP (120°F+), Texas Hill Country (100°F+), Florida (95°F + 90% humidity), Big Bend NP (95°F+).
These destinations are spring/fall/winter destinations. Summer visits require dawn/dusk-only outdoor activity + extensive A/C reliance.
What summer-travel guides don't tell you
Under-shared truth: cool-weather summer destinations book out earlier than most travellers realize. Recreation.gov 6-month booking window for premium PNW + Rockies + New England campgrounds typically clears within 1-15 minutes of opening at 8 AM local time. Set calendar reminders.
Second under-shared truth: 'shoulder summer' (late May + early September) offers nearly the same cool-weather benefit with dramatically lower crowds + reservations more available. Plan for late May or post-Labor-Day if flexible.