London Stargazing & Astronomy Report

Key Sky Quality Metrics

SQM (mag/arcsec²)

16.75

Bortle class

Class 9 (Class 9)

Darkness Quotient

14%

Dataset

April 2026

Inner city sky

London: The Practical Verdict

London, as a global metropolis in England, suffers from extreme light pollution. The sky here is classified as a severe urban sky, rendering the Milky Way entirely invisible from within the city. Observing conditions are strongly limited by skyglow originating from the dense urban environment.

At this site, stargazing efforts are best focused on the Moon, bright planets, and double stars, as these objects remain visible even under harsh lighting conditions. While narrowband imaging of bright nebulae is possible with careful setup, deep-sky visual observing and broadband targets like reflection nebulae or most galaxies are effectively out of reach.

For a meaningful improvement, consider travelling to Cockley Cley, situated to the north-north-east, roughly 135 km away. It offers significantly darker skies with a Bortle class of 5, making a broader range of targets accessible.

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

Limited nearby upgrade

Cockley Cley is the strongest nearby option but remains Bortle 5; the improvement is real but modest.

Moderate dark window

London'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 London?

No. London is a Bortle Class 9 sky with SQM 16.75, 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 London?

London is Bortle Class 9 (SQM 16.75), a severe urban sky for astronomy.

Is London good for stargazing?

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

Is London good for astrophotography?

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

What can you observe from London?

Primary targets from London 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 London?

The closest meaningfully darker mapped site is Therfield, about 59 km south south east of London, reaching Bortle 6.

When is the sky darkest in London?

The sky over London is darkest around January, December. Significant summer limitation: around 59 nights per year have no true astronomical darkness.

Is light pollution in London getting better or worse?

There is not yet enough long-term data to give a confident trend for London.

• Horsted Green

  Direction

  S

  Distance (km)

  63.2

  SQM

  20.34

  Bortle

  5

• Therfield

  Direction

  SSE

  Distance (km)

  59.1

  SQM

  19.92

  Bortle

  6

• Frittenden

  Direction

  SE

  Distance (km)

  63.5

  SQM

  19.95

  Bortle

  6

• Althorne

  Direction

  ENE

  Distance (km)

  64.1

  SQM

  19.78

  Bortle

  6

• Flexcombe

  Direction

  SW

  Distance (km)

  75

  SQM

  20.05

  Bortle

  6

• Cockley Cley

  Direction

  NNE

  Distance (km)

  135.2

  SQM

  20.67

  Bortle

  5