San Francisco Stargazing & Astronomy Report

Key Sky Quality Metrics

SQM (mag/arcsec²)

17.74

Bortle class

Class 9 (Class 9)

Darkness Quotient

21%

Dataset

May 2026

Inner city sky

San Francisco: The Practical Verdict

San Francisco is a major city in California with dense urban settings. The overall quality of its sky for astronomy is poor due to severe urban light pollution. The Milky Way is not visible from here, which significantly limits deep-sky observation prospects.

From this location, the best celestial targets are the Moon, planets, and bright stars. These are bright enough to pierce through the high levels of light pollution. More challenging targets like faint nebulae and broadband galaxies are best avoided due to the bright city sky.

For a better stargazing experience, head to Bolinas, California, roughly 30 km west north-west of San Francisco. This area offers a noticeable improvement with a Bortle 4 sky, making it a worthwhile destination for observing fainter deep-sky objects.

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

Bolinas, California sits about 30 km west north west and reaches Bortle 4, roughly 17x darker.

Good dark window

San Francisco'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 San Francisco?

No. San Francisco is a Bortle Class 9 sky with SQM 17.74, 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 San Francisco?

San Francisco is Bortle Class 9 (SQM 17.74), a severe urban sky for astronomy.

Is San Francisco good for stargazing?

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

Is San Francisco good for astrophotography?

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

What can you observe from San Francisco?

Primary targets from San Francisco 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 San Francisco?

The closest meaningfully darker mapped site is Fort McDowell, California, about 14 km south of San Francisco, reaching Bortle 6.

When is the sky darkest in San Francisco?

The sky over San Francisco is darkest around January, December.

Is light pollution in San Francisco getting better or worse?

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

• Bolinas, California

  Direction

  WNW

  Distance (km)

  30

  SQM

  20.84

  Bortle

  4

• Fort McDowell, California

  Direction

  S

  Distance (km)

  14.2

  SQM

  19.66

  Bortle

  6

• Harrington Creek Trail, California

  Direction

  S

  Distance (km)

  49.5

  SQM

  19.65

  Bortle

  6

• Sonoma County, California

  Direction

  NW

  Distance (km)

  109.1

  SQM

  20.67

  Bortle

  5

• 104 km NE

  Direction

  NE

  Distance (km)

  104

  SQM

  19.73

  Bortle

  6

• 163 km ENE

  Direction

  ENE

  Distance (km)

  163.1

  SQM

  20.12

  Bortle

  6