weather term
Visibility
The greatest distance at which an object can still be clearly seen against the sky, used to describe how fog, rain, snow or haze affect sight.
Visibility is reported in forecasts and by airports because it directly affects how safely people can drive, sail or fly. Dense fog can cut visibility to under 100 metres, while heavy rain or snow more commonly reduces it to somewhere between a few hundred metres and a couple of kilometres. Airports use visibility thresholds, along with cloud base height, to decide whether flights can take off or land safely.