Green Bay Stargazing & Astronomy Report
Light pollution and stargazing locations near Green Bay
- City
- Green Bay
- Country
- United States
- Latitude
- 44.5133
- Longitude
- -88.0133
Key Sky Quality Metrics
- SQM (mag/arcsec²)
- 17.92
- Bortle class
- Class 9 (Class 9)
- Darkness Quotient
- 22%
- Dataset
- March 2026
Inner city sky
Stargazing in Green Bay
Green Bay is a mid-sized waterfront city in north-eastern Wisconsin, best known for its position on Green Bay and its strong sporting identity.
With a Darkness Quotient of 22%, Green Bay sits in the High Light Pollution tier — brighter than many smaller regional towns, though not as overwhelmingly washed out as the very brightest global city centres.
For practical observing from within the city, the Moon, planets, double stars and the brightest open clusters are the most reliable targets. Brighter showpiece objects such as Orion Nebula can still be attempted, but faint galaxies, dim nebulae and the Milky Way are largely lost in the urban glow.
Meaningfully darker skies are available outside the city with a fairly modest drive. The nearest reasonable step up is about 35 kilometres to the south-south-east, near Town of Franklin, Wisconsin, where conditions reach a genuinely useful darker-sky level.
The map shows Green Bay as part of a broad bright zone rather than a tiny isolated hotspot, with intense pink and red urban cores embedded in wider yellow and green glow. That tells you the city’s light dome spreads well beyond the centre and blends into neighbouring developed areas.
The clearest darker corridor on the map appears over the large darker strip to the east, with deeper grey and black tones also becoming more common further north and north-east away from the main concentration of lights. By contrast, the south and south-west look more interrupted by additional bright pockets, so the sky glow in those directions is less cleanly escaped.
Overall, Green Bay stands out as one of the brighter features in its immediate surroundings, but it is not hemmed in on every side by continuous major urban light. The map suggests that a relatively short journey can bring a noticeable improvement, while the deepest darkness lies further out beyond the city’s main glow.
Looking up from the city
Looking straight up over Green Bay, the zenith remains bright by astronomical standards, with SQM 17.92 corresponding to a strongly urban sky. Even overhead, the background never becomes properly dark, so contrast is reduced across much of the sky.
In practice, the familiar brighter constellations are still easy to trace, and the Moon and planets stand out well. What you lose are the subtler star fields and the richer texture between the brighter patterns, so the sky tends to look simpler and more washed out than it would from rural Wisconsin.
north - fair
About 15 kilometres north of Green Bay, the sky improves to a fair level, around Bortle 5, which is a noticeable step up from the city itself. Continue farther and conditions become good quite quickly, with genuinely dark skies reached at about 100 kilometres in this direction.
north-north-east - fair
Around 15 kilometres to the north-north-east, the sky is fair at roughly Bortle 5. This is one of the stronger directions from Green Bay, with genuinely dark skies becoming available at about 50 kilometres.
north-east - fair
At roughly 15 kilometres to the north-east, conditions are fair, around Bortle 5, so brighter deep-sky targets begin to benefit. Push farther on and genuinely dark skies are reached at about 50 kilometres.
east-north-east - fair
About 15 kilometres east-north-east of the city, the sky is fair at around Bortle 5. The improvement continues steadily, and very dark conditions are reached at about 100 kilometres in this direction.
east - fair
Around 15 kilometres east of Green Bay, the sky sits at a fair Bortle 5 level. A much stronger improvement follows farther out, with genuinely dark skies reached at about 50 kilometres.
east-south-east - marginal
At about 15 kilometres east-south-east, the sky is still only marginal, around Bortle 6, so city glow remains quite intrusive. Even so, this direction improves well with distance, reaching genuinely dark skies at about 50 kilometres.
south-east - marginal
Roughly 15 kilometres to the south-east, the sky remains marginal at about Bortle 6. Darker conditions do exist farther on, but they take longer to reach here, with genuinely dark skies appearing at about 100 kilometres.
south-south-east - fair
About 15 kilometres south-south-east of Green Bay, the sky is fair at around Bortle 5. This direction does improve, but the darkest conditions take a longer journey, with genuinely dark skies not turning up until about 200 kilometres out.
south - fair
Around 15 kilometres due south, the sky is fair at roughly Bortle 5, offering a worthwhile improvement over the city centre. Farther out the sky does get better for a while, but genuinely dark skies are not reached within the sampled distance in this direction.
south-south-west - marginal
At about 15 kilometres to the south-south-west, conditions are marginal at around Bortle 6. The sky improves somewhat farther out, but genuinely dark skies are not within the sampled radius in this direction.
south-west - marginal
Roughly 15 kilometres south-west of Green Bay, the sky is still marginal at around Bortle 6. There is some improvement with distance, including decent darker rural sky, but genuinely dark skies are not reached within the sampled radius.
west-south-west - marginal
About 15 kilometres west-south-west, the sky is marginal at around Bortle 6, with substantial urban glow still present. A much better step up appears farther out, and genuinely dark skies are reached at about 100 kilometres in this direction.
west - marginal
Around 15 kilometres west of the city, conditions remain marginal at roughly Bortle 6. The view improves significantly beyond that, with genuinely dark skies becoming available at about 100 kilometres.
west-north-west - marginal
At about 15 kilometres west-north-west, the sky is marginal at around Bortle 6. This direction does reach good rural conditions farther out, but genuinely dark skies are not within the sampled radius.
north-west - marginal
Roughly 15 kilometres to the north-west, the sky is marginal at about Bortle 6. Keep going and conditions improve strongly, with genuinely dark skies reached at about 100 kilometres.
north-north-west - marginal
About 15 kilometres north-north-west of Green Bay, the sky is marginal at around Bortle 6. This direction improves quickly, with genuinely dark skies reached at about 50 kilometres.
zenith - poor
Looking straight up from Green Bay itself, the zenith is poor, with a Bortle 9 sky and an SQM reading of 17.92. The brightest constellations are still visible, but the background is washed bright enough that faint stars and the Milky Way are overwhelmed by the city’s light dome.
-
Near Ontonagon Township, Michigan
- Direction
- NW
- Distance (km)
- 267.9
- SQM
- 21.58
- Bortle
- 3
Milky Way visible, broadband DSO imaging
-
Near Michigan
- Direction
- ESE
- Distance (km)
- 113.6
- SQM
- 21.34
- Bortle
- 3
Milky Way visible, broadband DSO imaging
-
Near Town of Franklin, Wisconsin
- Direction
- SSE
- Distance (km)
- 35
- SQM
- 20.87
- Bortle
- 4
Bright nebulae, galaxies, narrowband imaging
Genuinely dark skies are not right on Green Bay’s doorstep, but they are much more accessible than they are from many larger cities. The nearest really worthwhile improvement is about 35 kilometres to the south-south-east, near Town of Franklin, Wisconsin, where conditions reach Bortle 4.
If you are willing to go farther, even darker Bortle 3 skies turn up about 115 kilometres to the east-south-east near Michigan. That means Green Bay offers a realistic split between quick local improvement and a longer trip for more serious deep-sky observing.
-
Within 50 km
- Place
- Near Town of Franklin, Wisconsin
- Direction
- SSE
- Distance (km)
- 35
- SQM
- 20.87
- Bortle
- 4
-
Within 200 km
- Place
- Near Michigan
- Direction
- ESE
- Distance (km)
- 113.6
- SQM
- 21.34
- Bortle
- 3
-
Within 500 km
- Place
- Near Ontonagon Township, Michigan
- Direction
- NW
- Distance (km)
- 267.9
- SQM
- 21.58
- Bortle
- 3
Long-term sky trend
Green Bay’s night sky has shown a slight long-term improvement in the measurements, rising from SQM 17.67 in the earliest record to 17.99 in the latest one. The fitted trend is gentle rather than dramatic, at about 0.0104 SQM per year.
That is encouraging, but in practical terms the city still remains heavily light-polluted for astronomy. The overall spread from 17.34 to 18.54 across 75 datasets shows some variation over time, though not enough to transform the basic observing experience from within the city.
From within Green Bay, the city-friendly targets are the obvious ones: the Moon, bright planets, double stars and the strongest open clusters. These can cut through heavy skyglow and still give rewarding views.
A few brighter deep-sky showpieces are possible with patience and realistic expectations, especially with binoculars or a telescope. For anything faint or wide-field — including the Milky Way, dim galaxies and subtle nebulae — a darker site outside the city makes a dramatic difference.
- Moon
- planets
- double stars
- brightest open clusters
- Orion Nebula (M42)
- brightest globular clusters
- Milky Way
- faint galaxies
- broadband nebulae
- meteor showers
Can you see stars from Green Bay?
Yes — you can still see the brighter stars and main constellation patterns from Green Bay. What drops away are the fainter background stars, so the sky looks much sparser than it would from the countryside.
Can you see the Milky Way from Green Bay?
Not realistically from within the city itself. With Green Bay at Bortle 9 and SQM 17.92, the Milky Way is effectively washed out by urban skyglow.
What Bortle class is Green Bay?
Green Bay is Bortle 9, which is an inner-city sky. In practical terms, that means heavy light pollution and a strong bias towards brighter astronomical targets.
What is the SQM reading for Green Bay?
The measured sky brightness for Green Bay is SQM 17.92. That is firmly on the bright side for astronomy and matches the strongly urban character of the night sky.
Where are the nearest dark skies from Green Bay?
The nearest really useful darker site in the supplied locations is Near Town of Franklin, Wisconsin, about 35 kilometres to the south-south-east, where conditions reach Bortle 4. For darker still skies, Near Michigan lies about 113.6 kilometres to the east-south-east and reaches Bortle 3.
Is Green Bay good for astrophotography?
It can work for lunar, planetary and some bright deep-sky astrophotography, but the city itself is not ideal for faint wide-field targets. For cleaner backgrounds and better contrast, you will get much better results by driving out to a darker site.
How far do you need to drive from Green Bay for darker skies?
A worthwhile improvement begins at about 35 kilometres, where Near Town of Franklin, Wisconsin reaches Bortle 4. If you want a more clearly dark-sky experience, Near Michigan at about 113.6 kilometres offers Bortle 3 conditions.