YozoraAtlas

How dark is the sky in Stockholm?

Sky darkness for 12 towns and parks in Stockholm, worked out from NASA satellite images of light at night (2025). None of them have skies of Bortle 4 or darker, where the Milky Way shows overhead. The darkest is Tyresta National Park (19.17, Bortle 6), the brightest Stockholm (17.20, Bortle 8). The bright core of the Milky Way never climbs clear of the horizon haze anywhere in Stockholm 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 Stockholm with every place marked

Darkest skies in Stockholm

  1. Tyresta National ParkBortle 619.17
  2. GustavsbergBortle 718.71
  3. VallentunaBortle 718.56

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 Stockholm

  1. StockholmBortle 817.20
  2. SollentunaBortle 817.73
  3. HuddingeBortle 817.94
  4. SödertäljeBortle 817.94
  5. HaningeBortle 818.07

All 12 places in Stockholm

Amber names are parks and certified dark-sky places. The figure is the Bortle class: 1 darkest, 9 city center.
Gustavsberg7Haninge8Huddinge8Märsta8Sollentuna8Stockholm8Södertälje8Tumba8Tyresta National Park6Upplands Väsby8Vallentuna7Åkersberga7