| Kenai Fjords National Park | November | July | 7755.0 |
| Gates of the Arctic National Park | November | August | 1589.5 |
| Wrangell-St. Elias National Park | January | July | 918.7 |
| Glacier Bay National Park | February | July | 637.3 |
| Isle Royale National Park | January | August | 509.8 |
| North Cascades National Park | December | August | 455.1 |
| Katmai National Park | February | July | 374.9 |
| Voyageurs National Park | April | August | 259.6 |
| Denali National Park | January | July | 124.9 |
| Lake Clark National Park | January | July | 114.9 |
| Theodore Roosevelt National Park | December | July | 57.6 |
| Acadia National Park | February | August | 57.3 |
| Glacier National Park | February | July | 50.5 |
| Yellowstone National Park | November | July | 45.3 |
| Crater Lake National Park | January | July | 36.5 |
| Badlands National Park | December | July | 24.7 |
| Mount Rainier National Park | February | July | 22.3 |
| Great Sand Dunes National Park | January | June | 20.6 |
| Mesa Verde National Park | January | July | 16.5 |
| Great Basin National Park | December | July | 15.5 |
| Lassen Volcanic National Park | March | July | 15.5 |
| Grand Teton National Park | December | July | 15.2 |
| Shenandoah National Park | January | October | 12.7 |
| Capitol Reef National Park | January | May | 12.5 |
| Canyonlands National Park | January | May | 11.2 |
| Bryce Canyon National Park | January | September | 10.6 |
| Wind Cave National Park | January | July | 10.2 |
| Gateway Arch National Park | January | July | 9.9 |
| Mammoth Cave National Park | January | July | 8.0 |
| Kings Canyon National Park | February | July | 8.0 |
| Olympic National Park | December | August | 7.9 |
| Rocky Mountain National Park | February | July | 7.9 |
| Black Canyon of the Gunnison National Park | December | July | 7.8 |
| New River Gorge National Park and Preserve | January | July | 7.0 |
| Arches National Park | January | June | 6.4 |
| Indiana Dunes National Park | January | July | 6.2 |
| Sequoia National Park | February | July | 5.2 |
| Big Bend National Park | August | March | 5.1 |
| Yosemite National Park | January | July | 4.8 |
| Chiricahua National Park | August | March | 4.7 |
| Zion National Park | January | June | 4.7 |
| Great Smoky Mountains National Park | January | July | 3.8 |
| Saguaro National Park | September | March | 3.8 |
| Redwood National Park | February | July | 3.7 |
| Cuyahoga Valley National Park | January | July | 3.7 |
| Virgin Islands National Park | September | March | 3.5 |
| Carlsbad Caverns National Park | January | July | 3.4 |
| Petrified Forest National Park | January | June | 3.2 |
| Grand Canyon National Park | January | July | 3.1 |
| Guadalupe Mountains National Park | January | March | 3.0 |
| Joshua Tree National Park | July | March | 2.8 |
| Channel Islands National Park | January | July | 2.8 |
| Everglades National Park | September | February | 2.7 |
| Kobuk Valley National Park | February | October | 2.7 |
| National Park of American Samoa | June | April | 2.5 |
| White Sands National Park | January | March | 2.5 |
| Hot Springs National Park | January | June | 2.5 |
| Congaree National Park | January | March | 2.2 |
| Death Valley National Park | June | March | 2.1 |
| Pinnacles National Park | September | March | 1.9 |
| Dry Tortugas National Park | October | June | 1.8 |
| Biscayne National Park | October | July | 1.8 |
| Hawai'i Volcanoes National Park | September | January | 1.5 |
