YozoraAtlas

How dark is the sky in North Dakota?

Sky darkness for 5 towns and parks in North Dakota, worked out from NASA satellite images of light at night (2025). 2 of them have skies of Bortle 4 or darker, where the Milky Way shows overhead. The darkest is Theodore Roosevelt National Park (21.34, Bortle 4), the brightest Fargo (17.58, Bortle 8).

19 Bortle class, 1 pristine to 9 city center park or dark-sky place city

Numbers like 21.95 or 16.97 are the brightness of the sky overhead on a clear, moonless night, in mag/arcsec². The scale runs backwards: a lower number means a brighter sky, from about 22 for a natural sky to about 17 in a city center.
How the readings are made

NASA satellite night-lights map of North Dakota with every place marked

Darkest skies in North Dakota

  1. Theodore Roosevelt National ParkBortle 421.34
  2. Fort Stevenson State ParkBortle 421.25

Among the places on this site. Plenty of land between them is just as dark, with no town or park to name it by.

Brightest city skies in North Dakota

  1. FargoBortle 817.58
  2. BismarckBortle 817.86
  3. Grand ForksBortle 818.12

All 5 places in North Dakota

Amber names are parks and certified dark-sky places. The figure is the Bortle class: 1 darkest, 9 city center.
Bismarck8Fargo8Fort Stevenson State Park4Grand Forks8Theodore Roosevelt National Park4