How dark is the sky in Belgium?
Sky darkness for 27 towns and parks in Belgium, 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 Entre-Sambre-et-Meuse National Park (21.23, Bortle 4), the brightest Brussels (18.17, Bortle 8).
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
Darkest skies in Belgium
- Entre-Sambre-et-Meuse National ParkWallonia · Bortle 421.23
- Deux Ourthes Nature ParkWallonia · Bortle 421.16
Among the places on this site. Plenty of land between them is just as dark, with no town or park to name it by.
Darkest place in each region of Belgium
| Region | Places | Dark places Bortle 1 to 4 | Darkest place |
|---|---|---|---|
| Brussels | 1 place | 0 dark | Brussels18.17 · Bortle 8 |
| Flanders | 16 places | 0 dark | Bosland National Park20.14 · Bortle 5 |
| Wallonia | 10 places | 2 dark | Entre-Sambre-et-Meuse National Park21.23 · Bortle 4 |