London Stargazing & Astronomy Report

Key Sky Quality Metrics

SQM (mag/arcsec²)

17.99

Bortle class

Class 9 (Class 9)

Darkness Quotient

23%

Dataset

April 2026

Inner city sky

London: The Practical Verdict

London, Ontario, is a mid-sized Canadian city with a dense urban environment. The sky here falls into the 'Severe urban sky' category, offering extremely limited opportunities for astronomy due to significant light pollution. The Milky Way is completely obscured, and deep-sky observing is inherently challenging.

Nonetheless, brighter celestial objects like the Moon, planets, and double stars remain viable, as do solar system events such as eclipses. With care, narrowband imaging techniques might reveal brighter nebulae, but reflections and low-surface-brightness targets are ill-suited to this environment.

For some improvement, a trip to Brown Brothers (Wrack), Ontario, to the east-south-east could provide modestly better viewing conditions. However, the gains are limited compared to the effort, and significant darkness would require longer distances.

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

Brown Brothers (Wrack), Ontario is the strongest nearby option but remains Bortle 5; the improvement is real but modest.

Good 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 17.99, 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 17.99), 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 Thames Centre, Ontario, about 20 km east south east of London, reaching Bortle 6.

When is the sky darkest in London?

The sky over London is darkest around January, December.

Is light pollution in London getting better or worse?

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

• Thames Centre, Ontario

  Direction

  ESE

  Distance (km)

  19.7

  SQM

  20.05

  Bortle

  6

• Warwick, Ontario

  Direction

  W

  Distance (km)

  59.8

  SQM

  20.21

  Bortle

  6

• Ratzburg, Ontario

  Direction

  NE

  Distance (km)

  60.1

  SQM

  20.12

  Bortle

  6

• 52, Ontario

  Direction

  E

  Distance (km)

  59.3

  SQM

  19.99

  Bortle

  6

• Brown Brothers (Wrack), Ontario

  Direction

  ESE

  Distance (km)

  102.2

  SQM

  20.58

  Bortle

  5

• Kingsville, Ontario

  Direction

  SW

  Distance (km)

  187.3

  SQM

  20.40

  Bortle

  5