Markham Stargazing & Astronomy Report

Key Sky Quality Metrics

SQM (mag/arcsec²)

17.70

Bortle class

Class 9 (Class 9)

Darkness Quotient

21%

Dataset

April 2026

Inner city sky

Markham: The Practical Verdict

Markham, situated in the Ontario region of Canada, is a mid-sized suburban city contributing to the wider light pollution zone of Toronto to the south. As such, the sky quality here falls under severe urban conditions, with a Bortle Class 9 reading, indicative of heavy light pollution that obscures faint objects entirely.

From this location, most deep-sky targets are beyond reach. The Milky Way is entirely invisible. Observational focus is best directed towards the Moon, planets, and bright stars, which are still prominent. Imaging enthusiasts may consider narrowband efforts but will face notable challenges from the bright sky background.

Serious observers aiming to experience richer starfields and fainter objects will find the nearest significant improvement at South Frontenac, Ontario, east-north-east of Markham. This site offers considerably darker skies at Bortle Class 4 and is worth considering for a more productive night out.

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

South Frontenac, Ontario sits about 236 km east north east and reaches Bortle 4, roughly 20x darker.

Good dark window

Markham'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 Markham?

No. Markham is a Bortle Class 9 sky with SQM 17.70, 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 Markham?

Markham is Bortle Class 9 (SQM 17.70), a severe urban sky for astronomy.

Is Markham good for stargazing?

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

Is Markham good for astrophotography?

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

What can you observe from Markham?

Primary targets from Markham 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 Markham?

The closest meaningfully darker mapped site is Mono, Ontario, about 52 km west north west of Markham, reaching Bortle 7.

When is the sky darkest in Markham?

The sky over Markham is darkest around January, December.

Is light pollution in Markham getting better or worse?

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

• Sutton, Ontario

  Direction

  ESE

  Distance (km)

  53.6

  SQM

  19.85

  Bortle

  6

• Scugog, Ontario

  Direction

  ENE

  Distance (km)

  55.4

  SQM

  19.82

  Bortle

  6

• Niagara County, New York

  Direction

  SE

  Distance (km)

  73.5

  SQM

  20.24

  Bortle

  6

• Mono, Ontario

  Direction

  WNW

  Distance (km)

  52.2

  SQM

  19.44

  Bortle

  7

• South Frontenac, Ontario

  Direction

  ENE

  Distance (km)

  235.6

  SQM

  20.97

  Bortle

  4