Markham Stargazing & Astronomy Report

Key Sky Quality Metrics

SQM (mag/arcsec²)

17.70

Bortle class

Class 9 (Class 9)

Darkness Quotient

21%

Dataset

May 2026

Inner city sky

Markham: The Practical Verdict

Markham, a mid-size suburban city in Ontario, Canada, presents challenges for stargazing enthusiasts. The city is shrouded in severe urban sky conditions, which significantly limit astronomical observation. High light pollution from sources such as Toronto to the south dominates the skies, making it difficult to see faint celestial objects.

Under these conditions, the Milky Way is not visible. However, you can still observe bright celestial bodies like the Moon, planets, and some bright stars. For those with appropriate equipment, narrowband imaging could yield results, although visual deep-sky observing is poor.

For those seeking slightly improved observing conditions, Garden Hill, Ontario, about 75 km east north-east, offers a modest upgrade. Nevertheless, light pollution remains a factor and major breakthroughs in sky quality are not to be expected.

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

Garden Hill, Ontario is the strongest nearby option but remains Bortle 5; the improvement is real but modest.

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 Garden Hill, Ontario, about 77 km east north east of Markham, reaching Bortle 5.

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.

• Garden Hill, Ontario

  Direction

  ENE

  Distance (km)

  77.1

  SQM

  20.44

  Bortle

  5

• Selwyn, Ontario

  Direction

  NE

  Distance (km)

  91.8

  SQM

  20.31

  Bortle

  5

• Fairfield, Pennsylvania

  Direction

  SSW

  Distance (km)

  194.9

  SQM

  20.29

  Bortle

  6