YozoraAtlas

How dark is the sky in Trøndelag?

Sky darkness for 8 towns and parks in Trøndelag, worked out from NASA satellite images of light at night (2025). 6 of them have skies of Bortle 4 or darker, where the Milky Way shows overhead. The darkest is Børgefjell National Park (21.91, Bortle 2), the brightest Trondheim (17.62, Bortle 8). The bright core of the Milky Way never climbs clear of the horizon haze anywhere in Trøndelag while the sky is fully dark; the rest of the band passes overhead, with the longest moonless nights from October to March.

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 Trøndelag with every place marked

Darkest skies in Trøndelag

  1. Børgefjell National ParkBortle 221.91
  2. Lierne National ParkBortle 221.91
  3. Blåfjella-Skjækerfjella National ParkBortle 321.88
  4. Gressåmoen National ParkBortle 321.88
  5. Dovrefjell-Sunndalsfjella National ParkBortle 321.84

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 Trøndelag

  1. TrondheimBortle 817.62
  2. LevangerBortle 619.45

All 8 places in Trøndelag

Amber names are parks and certified dark-sky places. The figure is the Bortle class: 1 darkest, 9 city center.
Blåfjella-Skjækerfjella National Park3Børgefjell National Park2Dovrefjell-Sunndalsfjella National Park3Gressåmoen National Park3Levanger6Lierne National Park2Skarvan and Roltdalen National Park4Trondheim8