Decatur, IL — light pollution & stargazing
Decatur, Illinois has a light-pollution rating of about Bortle 8 — a city sky (very poor — city glow) — measured from VIIRS 2024 satellite night-lights at 53 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 Taylorville, IL (about 27 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 Decatur tonight
- Estimated Bortle class
- 8 of 9
- VIIRS radiance (town center)
- 53 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 Decatur
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 Decatur's sky toward truly dark skies.
| Town | State | Bortle | Sky | Drive |
|---|---|---|---|---|
| Taylorville | IL | 7 | Suburban / urban transition | 27 mi |
| Chatham | IL | 6 | Bright suburban sky | 41 mi |
| Wildwood | MO | 5 | Suburban sky | 125 mi |
| Caledonia | WI | 4 | Rural / suburban transition | 210 mi |
Frequently asked questions
- Can you see the Milky Way from Decatur, IL?
- Not really. At about Bortle 8 the Milky Way is not visible from Decatur — the sky is too light-polluted. The nearest genuinely dark skies are around Taylorville, IL, about 27 mi away.
- How dark is the sky in Decatur?
- Decatur 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 53 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 Decatur?
- The nearest town with genuinely darker skies is Taylorville, IL — about 27 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 Decatur 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 Illinois
See every town's darkness rating in Illinois, learn to read the Bortle scale, or check tonight's Moon phase.