Cities with the least light pollution in Switzerland

Light pollution - the brightening of the night sky from artificial sources - affects sleep quality, disrupts circadian rhythms, and has measurable ecological effects documented by environmental scientists. For people sensitive to light at night, or simply seeking darker skies for wellbeing and stargazing, proximity to high-radiance urban centres matters when choosing where to live or spend time.

ClearSpot measures night-sky radiance from VIIRS (Visible Infrared Imaging Radiometer Suite) satellite data, aggregated on a hexagonal H3 grid and calibrated to the Bortle dark-sky scale (1 = darkest, 9 = severely light-polluted). The scores below represent the average radiance within each city's administrative footprint - cities entirely within dense urban agglomerations will score higher (more pressure) than those on the rural fringe.

The 50 cities below register the lowest light pollution burden in Switzerland on ClearSpot's scale. A score near 100% indicates minimal documented light radiance from the city's own footprint; this does not necessarily mean total darkness, as nearby urban centres may contribute ambient light at ground level.