Regional Weather in Hong Kong - Explanatory notes

Explanatory Notes

Air temperature and relative humidity reporting

Air temperatures and relative humidities shown on this webpage are instantaneous readings recorded at the automatic weather station, while air temperatures and relative humidities in the hourly bulletin "Current Weather" are manually taken by weather observers during a ten-minute period before the end of the hour. The temperatures and relative humidities on the hour shown on this webpage and the temperatures and relative humidities reported in the hourly bulletin "Current Weather" may be taken at different instants and hence may not be the same.

Wind barbs

	:	calm
VRB	:	variable
	:	Easterly wind of 18 kilometres per hour
	:	Easterly wind of 90 kilometres per hour

Symbol		Descriptive Term	Beaufort Force
	:	Strong force wind	Force 6
	:	Gale force wind	Force 8
	:	Storm force wind	Force 10
	:	Hurricane force wind	Force 12

Visibility reporting

Visibility is reported according to World Meteorological Organization guidelines as summarized in the following table:

Measured Visibility	Rounded down to the nearest
100 metres - 4999 metres	100 metres
5 kilometres - 30 kilometres	1 kilometre
31 kilometres - 50 kilometres	5 kilometres

For example:
(i)	measured visibility of 1680 metres is reported as 1600 metres;
(ii)	measured visibility of 7900 metres is reported as 7 kilometres;
(iii)	measured visibility of 37 kilometres is reported as 35 kilometres.