| # | City | Bortle (est.) | Brightness | 2 classes darker |
|---|---|---|---|---|
| 1 | Bratislava | 7–8 | 255 | ~25 km NNE |
| 2 | Trnava | 7–8 | 255 | ~25 km WNW |
| 3 | Košice | 7–8 | 255 | ~25 km WNW |
| 4 | Nitra | 7–8 | 254 | ~25 km NE |
| 5 | Žilina | 6–7 | 253 | ~25 km NNW |
| 6 | Trenčín | 6–7 | 255 | ~25 km ENE |
| 7 | Prešov | 6–7 | 254 | ~25 km NNW |
| 8 | Banská Bystrica | 6–7 | 252 | ~25 km N |
| 9 | Martin | 6–7 | 202 | ~25 km ESE |
Brightness is the NASA VIIRS Black Marble 2016 value at the city centre on a 0–255 scale; 255 is saturated. Cities are ordered by estimated sky brightness, which also counts the light within 30 km.