YozoraAtlas

How dark is the sky in Olomouc Region?

Sky darkness for 6 towns and parks in Olomouc Region, 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 Jeseníky Protected Landscape Area (21.36, Bortle 4), the brightest Olomouc (18.90, Bortle 7). The bright core of the Milky Way never climbs clear of the horizon haze anywhere in Olomouc Region while the sky is fully dark; the rest of the band passes overhead, with the longest moonless nights from September to April.

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 Olomouc Region with every place marked

Darkest skies in Olomouc Region

  1. Jeseníky Protected Landscape AreaBortle 421.36
  2. Litovelské Pomoraví Protected Landscape AreaBortle 420.69

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 Olomouc Region

  1. OlomoucBortle 718.90
  2. PřerovBortle 619.47
  3. ProstějovBortle 519.59
  4. ŠumperkBortle 519.83

All 6 places in Olomouc Region

Amber names are parks and certified dark-sky places. The figure is the Bortle class: 1 darkest, 9 city center.
Jeseníky Protected Landscape Area4Litovelské Pomoraví Protected Landscape Area4Olomouc7Prostějov5Přerov6Šumperk5