Lisbon Stargazing & Astronomy Report

Key Sky Quality Metrics

SQM (mag/arcsec²)

17.37

Bortle class

Class 9 (Class 9)

Darkness Quotient

18%

Dataset

August 2026

Inner city sky

Lisbon: The Practical Verdict

Lisbon is the capital of Portugal, a major city with a dense urban setting. In terms of astronomy, it faces severe light pollution challenges, with an inner-city sky that heavily restricts astronomical observations. The most limiting factor here is the extreme light pollution, classifying it as a Bortle Class 9 site.

What the Lisbon sky does offer is a good view of the Moon, planets, and bright stars. These are the most reliable targets under such sky conditions. However, deep-sky observation is practically impossible, with the Milky Way and faint nebulae disappearing amidst the urban glow.

For those willing to travel, the site named Carregueiro to the south-east offers a markedly better sky quality, classified as Bortle 4 at around 135 km distance. This makes it a worthwhile trip for more serious stargazing efforts.

At a Glance

Overall

Severe urban sky - This is a severely light-polluted urban sky. Only the Moon, planets, bright stars, and a few specialist targets remain practical.

Milky Way

Not visible - The Milky Way is not visible from this sky.

Best targets from here

Moon, planets, bright stars, double stars, solar system events, narrowband imaging only with care

Do not prioritise

visual deep-sky observing, broadband galaxies, reflection nebulae, widefield Milky Way

Best nearby upgrade

Carregueiro sits about 134 km south east and reaches Bortle 4, roughly 30x darker.

Good dark window

Lisbon's longest dark windows fall in December and January, with the shortest nights around June and July. Plan deep-sky sessions around the autumn and winter months for the best combination of long nights and true astronomical darkness.

Frequently Asked Questions

Can you see the Milky Way from Lisbon?

No. Lisbon is a Bortle Class 9 sky with SQM 17.37, so the Milky Way is not visible from the city. For Milky Way photography, look for a Bortle 4 or darker site.

What Bortle class is Lisbon?

Lisbon is Bortle Class 9 (SQM 17.37), a severe urban sky for astronomy.

Is Lisbon good for stargazing?

Not for serious deep-sky observing. Lisbon is a severe urban sky where the Moon, planets, and a handful of bright targets are the realistic options from the city itself.

Is Lisbon good for astrophotography?

Broadband deep-sky imaging is heavily compromised from Lisbon and a Bortle 4 or darker site is strongly recommended. Even narrowband imaging is difficult from Lisbon without careful processing.

What can you observe from Lisbon?

Primary targets from Lisbon include Moon, planets, bright stars, double stars, solar system events. Targets such as visual deep-sky observing, broadband galaxies, reflection nebulae are not realistic from this sky.

Where are darker skies near Lisbon?

The closest meaningfully darker mapped site is Castelo, about 19 km south of Lisbon, reaching Bortle 7.

When is the sky darkest in Lisbon?

The sky over Lisbon is darkest around January, December.

Is light pollution in Lisbon getting better or worse?

Long-term light pollution over Lisbon has been broadly stable across the available measurements.

• Castelo

  Direction

  S

  Distance (km)

  19.4

  SQM

  19.10

  Bortle

  7

• Figueiredo

  Direction

  W

  Distance (km)

  37.6

  SQM

  19.62

  Bortle

  6

• Cardela

  Direction

  SSE

  Distance (km)

  75.7

  SQM

  20.10

  Bortle

  6

• Alcácer do Sal

  Direction

  SE

  Distance (km)

  78.6

  SQM

  19.98

  Bortle

  6

• Valverde

  Direction

  NNE

  Distance (km)

  84.5

  SQM

  20.18

  Bortle

  6

• Carregueiro

  Direction

  SE

  Distance (km)

  134.1

  SQM

  21.08

  Bortle

  4