San Francisco Stargazing & Astronomy Report
Light pollution and stargazing locations near San Francisco
- City
- San Francisco
- Country
- United States
- Latitude
- 37.7749
- Longitude
- -122.4194
Key Sky Quality Metrics
- SQM (mag/arcsec²)
- 17.88
- Bortle class
- Class 9 (Class 9)
- Darkness Quotient
- 22%
- Dataset
- August 2026
Inner city sky
San Francisco: The Practical Verdict
San Francisco, a major city in California, offers a densely populated urban setting for stargazing, though with significant urban light interference. The overall quality is limited by high light pollution, making it unsuitable for observing faint astronomical objects. The key issue here is the city's light pollution, which completely obscures the Milky Way.
From this location, viewers can see the Moon, planets, and bright stars with relative ease, while narrowband imaging can be attempted with care. However, deep-sky objects such as broadband galaxies and reflection nebulae are heavily affected by the light pollution and are best avoided.
For those seeking a better viewing experience, travelling to 33274, California, about 120 km north-west, provides a substantial improvement with a Bortle 3 sky. This site offers clearer views of the night sky and is a worthwhile destination for serious astronomers.
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
- 33274, California sits about 118 km north west and reaches Bortle 3, roughly 24x 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 17.88, 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 17.88), 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 Five Brooks, California, about 38 km north west of San Francisco, reaching Bortle 5.
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.
north - fair
The north horizon shows a slight brightening. Workable for most targets above about 10 degrees elevation.
north-north-east - fair
The north-north-east horizon shows a slight brightening. Workable for most targets above about 10 degrees elevation.
north-east - marginal
The lower north-east sky is moderately light-polluted. Useful for bright targets above about 20 degrees only.
east-north-east - marginal
The lower east-north-east sky is moderately light-polluted. Useful for bright targets above about 20 degrees only.
east - marginal
The lower east sky is moderately light-polluted. Useful for bright targets above about 20 degrees only.
east-south-east - fair
A small artificial brightening near the east-south-east horizon. Star counts in this direction remain high above the lowest elevations.
south-east - fair
A small artificial brightening near the south-east horizon. Star counts in this direction remain high above the lowest elevations.
south-south-east - fair
Subtle skyglow on the south-south-east horizon. Faint stars below about 10 degrees here are slightly suppressed.
south - marginal
Persistent skyglow on the south horizon. Faint stars near the ground in this direction are lost.
south-south-west - fair
The south-south-west horizon is mostly dark with a hint of light pollution. Faint stars are accessible above about 10 degrees.
south-west - good
No visible glow on the south-west horizon. Stars are clear down to low elevation in this direction.
west-south-west - good
The west-south-west horizon is free of artificial brightening. Faint stars are visible to within a few degrees of the ground.
west - good
The west horizon is free of artificial brightening. Faint stars are visible to within a few degrees of the ground.
west-north-west - good
Clean, dark sky to the west-north-west. No visible artificial light source affects this quarter.
north-west - good
The north-west horizon is free of artificial brightening. Faint stars are visible to within a few degrees of the ground.
north-north-west - fair
Mild brightening on the north-north-west horizon. Faint stars at the very lowest elevation are dimmed; otherwise unaffected.
zenith - poor
Strong light pollution at the zenith. Limiting magnitude is around 3 to the unaided eye.
-
Five Brooks, California
- Direction
- NW
- Distance (km)
- 38.3
- SQM
- 20.37
- Bortle
- 5
-
Middleton Tract, California
- Direction
- SSE
- Distance (km)
- 56.9
- SQM
- 19.90
- Bortle
- 6
-
33274, California
- Direction
- NW
- Distance (km)
- 118
- SQM
- 21.33
- Bortle
- 3
-
Grand Island Road, California
- Direction
- ENE
- Distance (km)
- 83.5
- SQM
- 20.09
- Bortle
- 6
-
San Joaquin County, California
- Direction
- ESE
- Distance (km)
- 82.2
- SQM
- 19.93
- Bortle
- 6
-
31994, California
- Direction
- NNE
- Distance (km)
- 99
- SQM
- 19.53
- Bortle
- 7