San Luis, AZ — light pollution & stargazing
San Luis, Arizona has a light-pollution rating of about Bortle 8 — a city sky (very poor — city glow) — measured from VIIRS 2024 satellite night-lights at 85 nW/cm²/sr at the town center. The sky is bright enough to read by. Only the Moon, the planets, and the few brightest stars and clusters are visible — the constellations lose most of their fainter stars. The nearest genuinely darker skies are around Somerton, AZ (about 9 mi away, Bortle 7). Tonight's Moon phase, cloud cover, and aurora odds load live below, computed in your browser. This is a satellite upward-radiance proxy for planning, not a survey-grade sky-brightness measurement.
Stargazing in San Luis tonight
- Estimated Bortle class
- 8 of 9
- VIIRS radiance (town center)
- 85 nW/cm²/sr
- Naked-eye limiting mag.
- 4.1–4.5
- Milky Way
- not visible
City sky. A satellite upward-radiance proxy for planning — not a survey-grade sky-brightness reading.
What you can see from San Luis
The sky is bright enough to read by. Only the Moon, the planets, and the few brightest stars and clusters are visible — the constellations lose most of their fainter stars.
Darker skies within reach
The nearest town in each darker class — your ladder from San Luis's sky toward truly dark skies.
| Town | State | Bortle | Sky | Drive |
|---|---|---|---|---|
| Somerton | AZ | 7 | Suburban / urban transition | 9 mi |
| Fortuna Foothills | AZ | 6 | Bright suburban sky | 25 mi |
| San Diego Country Estates | CA | 5 | Suburban sky | 120 mi |
| New River | AZ | 4 | Rural / suburban transition | 180 mi |
Frequently asked questions
- Can you see the Milky Way from San Luis, AZ?
- Not really. At about Bortle 8 the Milky Way is not visible from San Luis — the sky is too light-polluted. The nearest genuinely dark skies are around Somerton, AZ, about 9 mi away.
- How dark is the sky in San Luis?
- San Luis rates a city sky — about Bortle 8, with a naked-eye limiting magnitude around 4.1–4.5. That comes from a VIIRS satellite night-lights reading of 85 nW/cm²/sr at the town center. It is a satellite proxy for planning, not a survey-grade measurement.
- Where is the nearest dark sky to San Luis?
- The nearest town with genuinely darker skies is Somerton, AZ — about 9 mi away at roughly Bortle 7. See the "darker skies within reach" list on this page for more options.
- Can I see the aurora from San Luis tonight?
- It depends on tonight's space weather. The live panel on this page reads the current NOAA aurora forecast for your latitude, along with cloud cover and the Moon — most U.S. locations only see aurora during strong geomagnetic storms.
The darkness rating is measured from VIIRS satellite night-lights at the town center and is a proxy for planning, not a survey-grade sky-brightness measurement — and the darkest skies are usually a short drive out of any town. Tonight's Moon, cloud, and aurora figures are live third-party forecasts that can change. See the methodology for sources and limits.
More in Arizona
See every town's darkness rating in Arizona, learn to read the Bortle scale, or check tonight's Moon phase.