YozoraAtlas

How dark is the sky in Madrid?

Sky darkness for 15 towns and parks in Madrid, worked out from NASA satellite images of light at night (2025). None of them have skies of Bortle 4 or darker, where the Milky Way shows overhead. The darkest is Guadarrama National Park (20.40, Bortle 5), the brightest Leganés (17.65, Bortle 8). Milky Way season in Madrid runs March to August: on moonless nights the bright core stands clear of the horizon, climbing to about 21° 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 Madrid with every place marked

Darkest skies in Madrid

  1. Guadarrama National ParkBortle 520.40
  2. AranjuezBortle 619.31
  3. Rivas-VaciamadridBortle 618.96

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 Madrid

  1. LeganésBortle 817.65
  2. MadridBortle 817.94
  3. AlcobendasBortle 818.04
  4. CosladaBortle 818.06
  5. MóstolesBortle 818.21

All 15 places in Madrid

Amber names are parks and certified dark-sky places. The figure is the Bortle class: 1 darkest, 9 city center.
Alcalá de Henares7Alcobendas8Aranjuez6Collado-Villalba7Coslada8Guadarrama National Park5Las Rozas de Madrid7Leganés8Madrid8Móstoles8Parla8Pozuelo de Alarcón8Rivas-Vaciamadrid6Torrejón de Ardoz8Valdemoro7