How should the state of visibility be determined?

The state of visibility should be determined by assessing atmospheric conditions, including factors like fog, rain, snow, and smoke, which can impair sight. Measurements can be taken using visibility sensors or by visual observation against known landmarks at a specific distance. Additionally, meteorological data, including humidity and wind speed, should be considered, as they can influence visibility levels. Regular reporting and updates from weather stations can help maintain accurate visibility assessments for safety and navigation purposes.