Light Pollution Map

Light Pollution Map helps answer a travel question that a weather forecast cannot: if the clouds clear, how dark is the site likely to be? Its layers include yearly satellite measurements of upward night-time radiance, modeled sky brightness and contributed Sky Quality Meter readings. Switching among years can reveal development around a once-dark location, while measurement points provide a reality check where observers have submitted them. Cloud and aurora overlays, observatory markers and polygon statistics extend the map beyond a coloured backdrop.

The layers do not all measure the same thing. A satellite sees light emitted upward; an observer cares about skyglow at ground level, and local lamps, terrain, humidity or snow can change the experience dramatically. The familiar colour bands are therefore a screening tool, not a promise of a particular Bortle class at the eyepiece. Use the map to compare regions and find candidate directions, then verify access, safety and present conditions. Its help page is worth reading before interpreting small colour differences or trends across datasets.