Perth Stargazing & Astronomy Report
Light pollution and stargazing locations near Perth
- City
- Perth
- Country
- Australia
- Latitude
- -31.9505
- Longitude
- 115.8605
Key Sky Quality Metrics
- SQM (mag/arcsec²)
- 17.63
- Bortle class
- Class 9 (Class 9)
- Darkness Quotient
- 20%
- Dataset
- March 2026
Inner city sky
Perth: The Practical Verdict
Perth is a major coastal city in Western Australia, isolated from Australia’s other big urban centres and known for its sprawling metropolitan footprint beside the Indian Ocean.
The city generally experiences Extreme Light Pollution, with a Darkness Quotient of just 20% — placing it among the more light-polluted major cities for urban stargazing.
In practical terms, brighter targets are the most realistic from within the city: the Moon, planets, double stars and the brightest open clusters. A few showpiece objects such as the Orion Nebula and the brightest globular clusters may be possible with compromise, but faint galaxies, dim nebulae and the Milky Way are largely overwhelmed by the city glow.
Truly dark skies are not close at hand from Perth, and a meaningful improvement requires a long drive out of the metro area. The nearest standout site in the supplied data is around 270 kilometres away to the north-north-east, near Near Western Australia, where conditions become genuinely dark.
The map shows Perth as a strong, concentrated core of white and pink light surrounded by red, orange, yellow and then blue-grey halos, a classic pattern for a large brightly lit urban area. The central glow is intense and broad enough to dominate much of the surrounding region, with the light dome spreading well beyond the city centre.
Away from the urban core, the map darkens unevenly rather than all at once. The most persistent brightness appears to run through the built-up corridor, while darker territory becomes more obvious farther out, especially once you move well away from the main metropolitan glow.
The surrounding countryside is noticeably darker than the city itself, but Perth still stands out as the overwhelmingly brightest feature in the crop. There are also smaller isolated patches of light in several directions, suggesting scattered settlements that interrupt otherwise darker skies.
How the sky looks overhead
Looking straight up from Perth, the overhead sky is heavily affected by urban skyglow rather than appearing truly black. With a zenith reading of 17.63 SQM, the background remains bright enough to wash out much of the finer star field.
In practice, the most familiar constellations still show up, but their fainter members tend to disappear and the sky can look sparse compared with a rural location. The brightest stars, planets and the Moon remain easy targets, while delicate naked-eye detail is greatly reduced.
This is the sort of sky where beginners can still enjoy simple observing, but experienced deep-sky observers will quickly feel the limits of the city environment.
north - poor
About 15 kilometres north of Perth, the sky is still poor for astronomy, sitting in the Bortle 8 range. It improves markedly farther out, with genuinely dark conditions reached at around 100 kilometres in this direction.
north-north-east - poor
At roughly 15 kilometres to the north-north-east, conditions are still poor, around Bortle 7. A much better step up appears farther out, with genuinely dark skies reached at about 100 kilometres.
north-east - poor
Around 15 kilometres north-east of the city, the sky remains poor, also in the Bortle 7 range. The picture improves strongly with distance, and genuinely dark skies arrive at about 100 kilometres.
east-north-east - poor
At around 15 kilometres east-north-east, the sky is still poor for serious deep-sky observing, in the Bortle 8 range. Much darker conditions are reachable farther out, with very dark skies appearing at about 100 kilometres.
east - poor
About 15 kilometres east of Perth, the sky is still poor, around Bortle 8. Conditions become much more rewarding farther out, with genuinely dark skies reached at around 100 kilometres.
east-south-east - poor
At roughly 15 kilometres east-south-east, the sky remains poor for stargazing, in the Bortle 8 range. A major improvement comes farther from the city, with genuinely dark skies at about 100 kilometres.
south-east - poor
Around 15 kilometres south-east of the city, the sky is still poor, at about Bortle 8. It gets much darker with distance, and genuinely dark conditions appear at around 100 kilometres.
south-south-east - poor
At around 15 kilometres south-south-east, the sky remains poor, in the Bortle 8 range. This direction improves more gradually, with genuinely dark skies not reached until about 200 kilometres out.
south - poor
About 15 kilometres south of Perth, the sky is still poor for most deep-sky work, around Bortle 8. Better rural darkness does exist in this direction, but genuinely dark skies only arrive at roughly 200 kilometres.
south-south-west - poor
At roughly 15 kilometres south-south-west, the sky remains poor, around Bortle 8. Darker conditions do develop with distance, with very dark skies reached at about 100 kilometres.
south-west - poor
Around 15 kilometres south-west of the city, the sky is poor and heavily affected by the urban glow, at Bortle 9. It improves substantially farther out, with genuinely dark skies reached at around 100 kilometres.
west-south-west - marginal
About 15 kilometres west-south-west of Perth, conditions are marginal rather than truly poor, at roughly Bortle 6. This is one of the quicker-improving directions, with very dark skies reached by around 50 kilometres.
west - marginal
At around 15 kilometres west, the sky is marginal for astronomy, around Bortle 6. This is one of Perth’s stronger directions for a quick escape, with very dark skies appearing at about 50 kilometres.
west-north-west - marginal
Roughly 15 kilometres west-north-west of the city, the sky is marginal, also around Bortle 6. It improves quite efficiently in this direction, with very dark skies reached at around 50 kilometres.
north-west - poor
About 15 kilometres north-west of Perth, the sky is still poor, around Bortle 7. A much stronger improvement comes farther out, with genuinely dark skies reached at about 100 kilometres.
north-north-west - poor
At roughly 15 kilometres north-north-west, the sky remains poor, around Bortle 7. Conditions do improve with distance, with genuinely dark skies reached at about 100 kilometres.
zenith - poor
Looking straight up from Perth itself, the zenith is poor, with an overhead sky in the Bortle 9 range. The brightest stars and familiar constellations are still visible, but the background sky is bright and the finer structure of the night sky is largely washed out, with the Milky Way effectively lost from view.
-
Near Western Australia
- Direction
- NNE
- Distance (km)
- 271.9
- SQM
- 21.83
- Bortle
- 2
Milky Way, faint nebulae, deep-sky imaging
-
Near Western Australia
- Direction
- WSW
- Distance (km)
- 284.5
- SQM
- 21.80
- Bortle
- 2
Milky Way, faint nebulae, deep-sky imaging
-
Near Western Australia
- Direction
- ENE
- Distance (km)
- 277.3
- SQM
- 21.78
- Bortle
- 2
Milky Way, faint nebulae, deep-sky imaging
Historical Light Pollution Trends
Perth’s long-term sky-brightness record is fairly steady overall. The earliest reading in this series was 17.74 SQM, while the latest is 17.63 SQM, so the city remains in a very bright urban range.
Across 76 datasets, the mean value is 17.8 SQM. The fitted trend is slight at 0.0019 SQM per year, which points to little overall change in the long-term picture.
The full historical range runs from 17.52 SQM to 22 SQM, showing that occasional much darker readings do appear in the record. Even so, the typical night sky over the city is consistently bright rather than genuinely dark.