YozoraAtlas

How dark is the sky in Lower Silesia?

Sky darkness for 17 towns and parks in Lower Silesia, worked out from NASA satellite images of light at night (2025). 10 of them have skies of Bortle 4 or darker, where the Milky Way shows overhead. The darkest is Śnieżnik Landscape Park (21.33, Bortle 4), the brightest Wrocław (18.24, Bortle 8). The bright core of the Milky Way never climbs clear of the horizon haze anywhere in Lower Silesia while the sky is fully dark; the rest of the band passes overhead, with the longest moonless nights from September 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

All 17 places in Lower Silesia

Amber names are parks and certified dark-sky places. The figure is the Bortle class: 1 darkest, 9 city center.
Barycz Valley Landscape Park4Bóbr Valley Landscape Park4Chełmy Landscape Park4Głogów6Jelenia Góra5Karkonosze National Park4Książ Landscape Park4Legnica6Lubin5Owl Mountains Landscape Park4Rudawy Landscape Park4Stołowe Mountains National Park4Wałbrzych5Wrocław8the Izera Dark Sky Park4Śnieżnik Landscape Park4Świdnica6