YozoraAtlas

How dark is the sky in Primorje-Gorski Kotar?

Sky darkness for 4 towns and parks in Primorje-Gorski Kotar, worked out from NASA satellite images of light at night (2025). 3 of them have skies of Bortle 4 or darker, where the Milky Way shows overhead. The darkest is Northern Velebit National Park (21.69, Bortle 4), the brightest Rijeka (19.07, Bortle 6). Milky Way season in Primorje-Gorski Kotar runs April to August: on moonless nights the bright core stands clear of the horizon, climbing to about 16° at its highest.

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 Primorje-Gorski Kotar with every place marked

Darkest skies in Primorje-Gorski Kotar

  1. Northern Velebit National ParkBortle 421.69
  2. Risnjak National ParkBortle 421.34
  3. Učka Nature ParkBortle 420.83

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 Primorje-Gorski Kotar

  1. RijekaBortle 619.07

All 4 places in Primorje-Gorski Kotar

Amber names are parks and certified dark-sky places. The figure is the Bortle class: 1 darkest, 9 city center.
Northern Velebit National Park4Rijeka6Risnjak National Park4Učka Nature Park4