The core clears 10 degrees during full darkness on most nights from March to August. In January, February, September, October, November and December it's out of reach, either too close to the Sun or too low in the dark.
Core score by month
| Month | Core score | Best week | Moon-free core hours a night | Average cloud |
|---|---|---|---|---|
| January | 0 | Core not visible | 0 | 65% |
| February | 0 | Core not visible | 0 | 65% |
| March | 1 | March 11 to 17 | 0.1 | 67% |
| April | 8 | April 7 to 13 | 0.8 | 62% |
| May | 14 | May 5 to 11 | 1.4 | 60% |
| June | 25 | June 1 to 7 | 2.2 | 55% |
| July | 28 | July 1 to 7 | 1.9 | 43% |
| August | 14 | August 1 to 7 | 1.1 | 45% |
| September | 3 | September 1 to 7 | 0.2 | 49% |
| October | 0 | Core not visible | 0 | 61% |
| November | 0 | Core not visible | 0 | 64% |
| December | 0 | Core not visible | 0 | 70% |
Times are for the best seven nights in each month. Moon-free means the moon is below the horizon. The core counts as visible above 10 degrees in full darkness, when the Sun is more than 18 degrees below the horizon.
The best nights in 2027
- May: May 6 is the best night. The core is above 10 degrees and the moon is down from 1:53 am to 3:13 am, with the moon 1% lit that night.
- June: June 3 is the best night. The core is above 10 degrees and the moon is down from 12:03 am to 2:13 am, with the moon 1% lit that night.
- July: July 1 is the best night. The core is above 10 degrees and the moon is down from 11:53 pm to 1:43 am, with the moon 5% lit that night.
Clock times are Mountain time with daylight saving applied. The best nights fall around the new moon, so the dates shift by about 11 days each year.
About Theodore Roosevelt National Park
Theodore Roosevelt National Park covers three units of the North Dakota badlands along the Little Missouri River. Bison, wild horses and prairie dogs are easy to see, and the scenic loop drives are short and easy. The scenery is layered red and tan buttes, with cottonwoods along the river.
Roosevelt first came to the Dakota Territory in 1883 to hunt bison, and after his wife and mother died on the same day in 1884, he spent time ranching here. His time in the badlands later shaped his conservation policies as president. It became a memorial park in 1947 and a national park in 1978.
Theodore Roosevelt National Park is a national park in North Dakota. The National Park Service places its center at 47.18 degrees north and 103.43 degrees west, and the sky calculations on this page use that point. Visitor information, fees and alerts are on the park's own page. National Park Service (opens in a new tab).
How Theodore Roosevelt National Park compares
Its best monthly core score of 28 ranks 49 of 54 national park units that can see the core. The highest is Lassen Volcanic National Park at 86, and the lowest is Voyageurs National Park at 13. Cloud at Theodore Roosevelt National Park runs from 43% in July to 70% in December.
The score ranks months and parks. It isn't a forecast for any night, and it leaves out local weather, smoke and light from nearby towns. How the core score works.
How dark is the sky?
The Park Service models how much artificial light brightens the sky across the lower 48. At the point used for Theodore Roosevelt National Park, it puts the added glow at about 99% of the natural brightness of a moonless sky (a ratio of 0.989). That makes it 35th darkest of the 47 parks it covers. Lower is darker. This is a model, not a reading taken at the park, and it describes one point, so the edges of a large park can differ.
Questions people ask
When is the best time to see the Milky Way at Theodore Roosevelt National Park?
May, June and July are the best months. The best week of 2027 is July 1 to 7.
Can you see the Milky Way at Theodore Roosevelt National Park all year?
The core clears 10 degrees during full darkness on most nights from March to August. In January, February, September, October, November and December it's out of reach, either too close to the Sun or too low in the dark.
How dark is the sky at Theodore Roosevelt National Park?
The Park Service models how much artificial light brightens the sky across the lower 48. At the point used for Theodore Roosevelt National Park, it puts the added glow at about 99% of the natural brightness of a moonless sky (a ratio of 0.989). That makes it 35th darkest of the 47 parks it covers. Lower is darker. This is a model, not a reading taken at the park, and it describes one point, so the edges of a large park can differ.
Does the moon matter at Theodore Roosevelt National Park?
Yes. A bright moon hides the Milky Way. The best night in July is July 1, when the moon is 5% lit and the core is above 10 degrees from 11:53 pm to 1:43 am.




