YozoraAtlas

How dark is the sky in Lazio?

Sky darkness for 7 towns and parks in Lazio, worked out from NASA satellite images of light at night (2025). 1 of them has skies of Bortle 4 or darker, where the Milky Way shows overhead. The darkest is Circeo National Park (20.51, Bortle 4), the brightest Rome (18.12, Bortle 8). Milky Way season in Lazio runs April to August: on moonless nights the bright core stands clear of the horizon, climbing to about 20° 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 Lazio with every place marked

Darkest skies in Lazio

  1. Circeo National ParkBortle 420.51

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 Lazio

  1. RomeBortle 818.12
  2. ApriliaBortle 619.05
  3. LatinaBortle 619.06
  4. Lido di OstiaBortle 619.32
  5. Guidonia MontecelioBortle 619.34

All 7 places in Lazio

Amber names are parks and certified dark-sky places. The figure is the Bortle class: 1 darkest, 9 city center.
Aprilia6Circeo National Park4Guidonia Montecelio6Latina6Lido di Ostia6Rome8Velletri6