Philadelphia Stargazing & Astronomy Report

Light pollution and stargazing locations near Philadelphia

City
Philadelphia
Country
United States
Latitude
39.9526
Longitude
-75.1652

Key Sky Quality Metrics

SQM (mag/arcsec²)
16.95
Bortle class
Class 9 (Class 9)
Darkness Quotient
16%
Dataset
May 2026

Inner city sky

Philadelphia: The Practical Verdict

Philadelphia is a major metropolis in Pennsylvania, burdened with extreme light pollution due to its dense urban environment. Astronomical quality here is categorised under a severe urban sky, where the Milky Way remains entirely elusive. The pervasive light pollution of Bortle Class 9 confines observations to a handful of bright objects.

In these conditions, your best stargazing targets from Philadelphia are the Moon, bright planets, and double stars. Solar system events remain viable pursuits. Narrowband imaging can be attempted with care, but visual deep-sky observing and widefield Milky Way photography should be avoided as they are heavily compromised by the bright sky.

For those seeking marginally darker skies, Hopewell Township in New Jersey offers some relief about 50 km to the south-south-west. While the improvement, listed under Bortle 6, remains modest, it provides better conditions for a broader astronomical experience.

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
Hopewell Township, New Jersey is the strongest nearby option but remains Bortle 6; the improvement is real but modest.
Good dark window
Philadelphia'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 Philadelphia?

No. Philadelphia is a Bortle Class 9 sky with SQM 16.95, 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 Philadelphia?

Philadelphia is Bortle Class 9 (SQM 16.95), a severe urban sky for astronomy.

Is Philadelphia good for stargazing?

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

Is Philadelphia good for astrophotography?

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

What can you observe from Philadelphia?

Primary targets from Philadelphia 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 Philadelphia?

The closest meaningfully darker mapped site is Hopewell Township, New Jersey, about 50 km south south west of Philadelphia, reaching Bortle 6.

When is the sky darkest in Philadelphia?

The sky over Philadelphia is darkest around January, December.

Is light pollution in Philadelphia getting better or worse?

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

north - marginal

Persistent skyglow on the north horizon. Faint stars near the ground in this direction are lost.

north-north-east - marginal

Moderate brightening on the north-north-east horizon. Star counts at low elevation here are reduced.

north-east - poor

A bright dome of skyglow sits on the north-east horizon. Faint stars are suppressed up to roughly 25 degrees elevation.

east-north-east - marginal

Moderate brightening on the east-north-east horizon. Star counts at low elevation here are reduced.

east - marginal

Persistent skyglow on the east horizon. Faint stars near the ground in this direction are lost.

east-south-east - marginal

Persistent skyglow on the east-south-east horizon. Faint stars near the ground in this direction are lost.

south-east - marginal

Moderate brightening on the south-east horizon. Star counts at low elevation here are reduced.

south-south-east - marginal

The lower south-south-east sky is moderately light-polluted. Useful for bright targets above about 20 degrees only.

south - marginal

A soft but obvious glow marks the south horizon. The lowest 15-20 degrees of sky in this direction are degraded.

south-south-west - marginal

Moderate brightening on the south-south-west horizon. Star counts at low elevation here are reduced.

south-west - marginal

Persistent skyglow on the south-west horizon. Faint stars near the ground in this direction are lost.

west-south-west - marginal

The lower west-south-west sky is moderately light-polluted. Useful for bright targets above about 20 degrees only.

west - marginal

A soft but obvious glow marks the west horizon. The lowest 15-20 degrees of sky in this direction are degraded.

west-north-west - marginal

Persistent skyglow on the west-north-west horizon. Faint stars near the ground in this direction are lost.

north-west - marginal

Moderate brightening on the north-west horizon. Star counts at low elevation here are reduced.

north-north-west - marginal

Persistent skyglow on the north-north-west horizon. Faint stars near the ground in this direction are lost.

zenith - poor

Overhead is dominated by skyglow. Only the brightest stars and planets are clear.

  • Hopewell Township, New Jersey
    Direction
    SSW
    Distance (km)
    49.8
    SQM
    19.95
    Bortle
    6
  • Wescoatville, New Jersey
    Direction
    SE
    Distance (km)
    50.6
    SQM
    19.62
    Bortle
    6
  • Maurice River Township, New Jersey
    Direction
    SSE
    Distance (km)
    73.5
    SQM
    20.00
    Bortle
    6
  • Furniss, Pennsylvania
    Direction
    W
    Distance (km)
    92.5
    SQM
    19.84
    Bortle
    6
  • Frisbie, Pennsylvania
    Direction
    NW
    Distance (km)
    110.7
    SQM
    20.14
    Bortle
    6
  • Delaware Water Gap, Pennsylvania
    Direction
    ESE
    Distance (km)
    112.8
    SQM
    20.16
    Bortle
    6