London Stargazing & Astronomy Report

Light pollution and stargazing locations near London

City
London
Country
Canada
Latitude
42.9849
Longitude
-81.2453

Key Sky Quality Metrics

SQM (mag/arcsec²)
17.85
Bortle class
Class 9 (Class 9)
Darkness Quotient
22%
Dataset
March 2026

Inner city sky

Stargazing in London, Ontario

London is a mid-sized city in south-western Ontario, set within a broad farming region between the Great Lakes. With a Darkness Quotient of 22%, London sits in the High Light Pollution tier, brighter than many smaller Ontario centres and firmly limited by urban skyglow.

From within the city, the Moon, planets, brighter double stars and the most conspicuous star clusters still come through well, but faint galaxies, the Milky Way and most diffuse nebulae are heavily washed out. A short drive improves things only modestly, while a more worthwhile change comes at around 75 kilometres to the north-north-east at Milverton, where the sky reaches a genuinely darker rural level.

The map shows London as one of the brighter cores in the area, with a broad pink-white centre surrounded by red, orange and yellow glow spreading well beyond the built-up area. That pattern tells you the city's light dome is not just a compact hotspot over downtown, but a sizeable pool of brightness that lifts much of the nearby sky too.

Away from the city, the colours cool into green, blue and then darker grey-blue patches, especially towards the south, south-east, north-west and farther north. The north-east and east look less favourable overall, with more scattered bright knots and less continuous dark territory, while the deepest-looking pockets on the map sit well away from the urban core rather than immediately outside it.

Compared with its surroundings, London is clearly a bright island in a mixed rural landscape. There are darker areas in several directions, but the map suggests the best gains come once you are properly beyond the city's halo rather than just on its edge.

Looking straight up from London

At the zenith, London measures 17.85 SQM, which corresponds to a very bright urban sky overhead. Even looking straight up, the background does not become fully dark, and the sky often has a grey or orange cast instead of a clean black one.

The main constellations remain easy enough to trace, along with the brighter guide stars and planets, but the finer star fields between them are thinned out. On transparent nights you can still pick out recognisable seasonal patterns, yet subtle features such as the Milky Way's mottling or faint naked-eye clusters are mostly lost in the glow.

north - fair

Fifteen kilometres to the north, the sky improves to Bortle 5, which is a fair step up from the city centre. Keep going and it becomes good by around 50 kilometres, with genuinely dark conditions only appearing much farther out, near 200 kilometres in this direction.

north-north-east - fair

Fifteen kilometres to the north-north-east, conditions are around Bortle 5, so the glow is reduced but still very present. This direction improves steadily, reaching good rural sky around 100 kilometres, with darker still conditions only much farther out.

north-east - marginal

Fifteen kilometres to the north-east, the sky is about Bortle 6, which is only a marginal improvement for deep-sky observing. Although it gets a bit better beyond that, genuinely dark skies are not reached within the sampled radius in this direction.

east-north-east - marginal

Fifteen kilometres to the east-north-east, the sky is also around Bortle 6, so local skyglow still dominates. There are some moderate improvements farther out, but genuinely dark skies are not within the sample radius in this direction.

east - poor

Fifteen kilometres to the east, the sky remains at Bortle 7, which is still poor for anything faint. Even farther out the pattern stays uneven, and genuinely dark skies are not reached within the sampled radius in this direction.

east-south-east - marginal

Fifteen kilometres to the east-south-east, the sky is about Bortle 6, giving only a limited gain over the city. If you continue much farther, this direction does eventually open into darker country, with good dark-sky conditions appearing at around 100 kilometres.

south-east - marginal

Fifteen kilometres to the south-east, the sky is around Bortle 6, so brighter deep-sky objects begin to improve but the background is still bright. This direction strengthens well with distance, reaching good rural sky by about 50 kilometres and very dark conditions by around 100 kilometres.

south-south-east - marginal

Fifteen kilometres to the south-south-east, conditions are around Bortle 6, still short of true dark sky. The improvement becomes much more noticeable farther out, with genuinely dark conditions arriving at roughly 50 kilometres.

south - marginal

Fifteen kilometres to the south, the sky is about Bortle 6, which is a modest gain but still not dark. Continue out into the countryside and this direction reaches genuinely dark conditions at around 50 kilometres.

south-south-west - marginal

Fifteen kilometres to the south-south-west, the sky is around Bortle 6, so the city still has a strong effect. A more substantial improvement arrives by roughly 50 kilometres, where the sky becomes properly dark for much more ambitious observing.

south-west - marginal

Fifteen kilometres to the south-west, the sky is about Bortle 6, offering some relief from the urban dome but not a dramatic change. It does improve to good rural quality farther out, though genuinely dark skies are not reached within the sampled radius in this direction.

west-south-west - marginal

Fifteen kilometres to the west-south-west, the sky is around Bortle 6, so faint targets remain difficult. There is better rural sky beyond that, but genuinely dark skies are not within the sample radius in this direction.

west - marginal

Fifteen kilometres to the west, the sky is about Bortle 6, which is only a moderate improvement. Conditions become patchy farther out and genuinely dark skies are not reached within the sampled radius in this direction.

west-north-west - marginal

Fifteen kilometres to the west-north-west, the sky is around Bortle 6, still affected by London's wider glow. This direction gets markedly better with distance, reaching good sky by around 50 kilometres and genuinely dark conditions by about 100 kilometres.

north-west - marginal

Fifteen kilometres to the north-west, the sky is about Bortle 6, so the city has loosened its grip but not disappeared. This is one of the stronger escape routes, with good sky by around 25 to 50 kilometres and very dark conditions near 100 kilometres.

north-north-west - fair

Fifteen kilometres to the north-north-west, the sky improves to Bortle 5, making this one of the better nearer directions. Keep heading that way and it reaches good sky around 50 kilometres, with genuinely dark conditions appearing by about 100 kilometres.

zenith - poor

Looking straight up from London, the zenith sits at Bortle 9, so the overhead sky remains strongly brightened rather than turning properly dark. The main constellations, brighter stars and planets are still easy to see, but the faint background star fields are heavily reduced and the Milky Way is generally lost.

  • Milverton, Ontario
    Direction
    NNE
    Distance (km)
    73.1
    SQM
    20.95
    Bortle
    4

    Bright nebulae, galaxies, narrowband imaging

Dark skies are not right on London's doorstep, but they are reachable with a moderate drive into the surrounding countryside. The nearest true dark-sky improvement is around 75 kilometres to the north-north-east at Milverton, where conditions reach Bortle 4 and the difference is obvious on a clear moonless night.

If you only head a short distance out of town, the sky usually improves a little rather than dramatically. The best results come once you are well clear of the city's glow, especially towards the north, south and south-east.

  • Within 100 km
    Place
    Milverton, Ontario
    Direction
    NNE
    Distance (km)
    73.1
    SQM
    20.95
    Bortle
    4
  • Within 200 km
    Place
    104 km SSE
    Direction
    SSE
    Distance (km)
    104
    SQM
    21.23
    Bortle
    4

Long-term sky brightness trend

Across 83 datasets, London's night sky has been broadly stable rather than changing sharply. The latest reading is 17.85 SQM, compared with 17.63 SQM in the earliest record, while the long-term mean sits at 18.01 SQM.

The full range, from 17.41 to 18.30 SQM, suggests that short-term variation from conditions and seasonal factors is more noticeable than any underlying long-term shift. The fitted trend is effectively flat, so London's sky has remained consistently bright over the period covered here.

London's sky is best treated as an urban observing base for bright, high-contrast targets. Lunar detail, planetary viewing, colourful double stars and a handful of bright clusters are all realistic and enjoyable from within the city.

Some showpiece deep-sky objects can still be attempted with care, especially with a telescope and filters, but they rarely look their best against such a bright background. For the Milky Way, galaxy hunting, wide-field nebula work and meteor watching, a darker rural site makes a very large difference.

  • Moon
  • planets
  • double stars
  • bright variable stars
  • brightest open clusters
  • Orion Nebula (M42)
  • Andromeda Galaxy as a faint glow
  • bright globular clusters
  • the brightest planetary nebulae
  • Milky Way
  • faint galaxies
  • broadband nebulae
  • meteor showers
  • dark nebulae
  • large diffuse emission nebulae

Can you see stars from London?

Yes, easily, but mostly the brighter stars and the main constellation patterns. The sky is bright enough that many fainter stars disappear from view, especially lower down where the light dome is strongest.

Can you see the Milky Way from London?

In most of the city, no, not as a clear naked-eye band. With a Bortle class of 9 and an SQM reading of 17.85, the background sky is usually too bright for the Milky Way to stand out.

What Bortle class is London?

London is Bortle Class 9 at this sampled location, which is an inner-city level sky. That means light pollution strongly limits faint deep-sky observing.

What is the SQM value in London?

The measured sky brightness is 17.85 SQM. In plain terms, that is a bright urban sky rather than a dark rural one.

Where are the nearest dark skies from London?

The nearest listed dark-sky option is Milverton, around 75 kilometres to the north-north-east, where the sky reaches Bortle 4 with an SQM of 20.95. There is also a darker area roughly 105 kilometres to the south-south-east.

Is London good for astrophotography?

It is workable for the Moon, planets and some narrowband imaging of brighter nebulae, but it is not ideal for wide-field nightscapes or faint galaxies. For cleaner backgrounds and much stronger contrast, a darker rural site is far better.

How far do you need to drive from London for darker skies?

A small improvement begins within a short drive, but the first clearly dark rural sky in the supplied data is around 75 kilometres away at Milverton. Some directions, especially south, south-south-east, north-west and north-north-west, also improve strongly once you are roughly 50 to 100 kilometres out.