The numerical visibility reading above represents the average of readings in the 10 minutes ending at the indicated time.
The visibility at Chek Lap Kok is provided by the visibility meter near the middle of the south runway of the Hong Kong International Airport. When this visibility meter cannot provide data, the visibility value will come from one of the neighbouring meters at the airport.
The reported visibility ranges between 100 metres and 50 kilometres. A visibility report of 100 metres refers to visibilities of 100 metres or less. A visibility report of 50 kilometres refer to visibilities of 50 kilometres or more.
Logarithmic scale is used to facilitate reading, especially at low visibility values.
Despite quality control, the automatic visibility reading may occasionally be affected by noises and interferences.