How dark is the sky in Italy?
Sky darkness for 160 towns and parks in Italy, worked out from NASA satellite images of light at night (2025). 48 of them have skies of Bortle 4 or darker, where the Milky Way shows overhead. The darkest is Gennargentu National Park (21.61, Bortle 4), the brightest Milan (18.02, 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 Italy
- Gennargentu National ParkSardinia · Bortle 421.61
- Rieserferner-Ahrn Nature ParkTrentino-Alto Adige · Bortle 421.61
- Sexten Dolomites Nature ParkTrentino-Alto Adige · Bortle 421.53
- Fanes-Sennes-Prags Nature ParkTrentino-Alto Adige · Bortle 421.52
- Stelvio National ParkLombardy · Bortle 421.46
Among the places on this site. Plenty of land between them is just as dark, with no town or park to name it by.