Hong Kong Observatory
The Hong Kong Observatory was established in 1883, mainly to provide time
service and weather information for the safe navigation of ships. Since then, it has
evolved in line with community needs, providing services in weather forecasting,
climatology, hydrometeorology, physical oceanography, and radiation monitoring and
assessment. The Observatory also administers the official time standard for Hong
Kong, provides astronomical information, maintains a seismological monitoring
network and operates the tsunami warning system in Hong Kong.
The Observatory issues weather forecasts and warnings of hazardous weather to
the public, mariners, the aviation community as well as special users such as
container terminals and transport operators. Whenever Hong Kong is threatened by
tropical cyclones, warnings are widely disseminated through the mass media. A
colour-coded rainstorm warning system warns people of heavy rain. The Observatory
also issues warnings on thunderstorms, landslips, fire danger, strong monsoon, cold
and very hot weather as well as frost. This year, the Observatory commenced issuing
ultraviolet (UV) index forecasts to enable members of the public to consider
appropriate protective measures against the harm from UV radiation during outdoor
Objective guidance for the issuance of rainstorm and landslip warnings is
provided by a computer-based Nowcasting System developed by the Observatory
itself. This system automatically analyses radar and raingauge data and forecasts the
rainfall distribution within the territory in the few hours that follow. Under the World
Weather Research Programme of the World Meteorological Organisation, the system
was selected as one of the very short range forecasting systems for the Beijing 2008
Olympic Games Forecast Demonstration Project.
To support the 2008 Olympic equestrian event in Hong Kong, the Observatory
has developed a measuring system to monitor a horse's heat stress. The system
started collecting climatological data at the competition venues in June.
The Observatory's meteorologists host regular TV and radio weather
programmes, and conduct media briefings in case of adverse weather. Weather
information is also disseminated through the Observatory's website and its automatic
Dial-a-Weather System. The Observatory's website continues to be one of the most
popular government websites, with 918 million page hits in 2006, an increase of 75
per cent compared with 2005.
To promote public education and awareness about hazardous weather, the
Observatory continues to organise a programme of meteorological courses for
members of the public and government personnel, exhibitions, scientific lectures,
Open Days and guided tours of the Observatory, with a total of about 20 000
The Observatory's Airport Meteorological Office (AMO) is responsible for the
provision of weather services at the Hong Kong International Airport (HKIA) and for
the Hong Kong Flight Information Region. About 142 000 flight documents were
provided by the AMO for aircraft departing the HKIA, an increase of 7.5 per cent
compared with 2005.
Radiation Measurement and Assessment
The Observatory operates a network of 10 radiation monitoring stations to
continuously monitor the ambient radiation levels in Hong Kong and conducts
radiological measurements on samples of air, soil, water and food.
In the event of a nuclear emergency, the Observatory will immediately intensify
radiation monitoring, assess the radiological consequences and provide technical
advice to the relevant policy bureaux on the appropriate protective actions to take.
Climatological, Oceanographic and Geophysical Services
The Observatory provides climatological information to meet the needs of users
and activities ranging from recreation to engineering design, environmental impact
analysis and litigation. It also carries out studies on climate change and the impact of
weather and climate on health. The Observatory issues in March each year an outlook
on the annual rainfall and the number of tropical cyclones likely to affect Hong Kong.
In 2006, the Observatory started issuing seasonal forecasts on the temperature and
the rainfall in Hong Kong once every three months on an experimental basis.
The Observatory produces an annual tide table for Hong Kong. It also provides
assessments of the probabilities of occurrence of extreme storm surges and advice on
oceanographic matters to other government departments and the engineering
To monitor earthquake activities in the vicinity of Hong Kong, the Observatory
operates a network of eight short-period seismograph stations. Long-period
seismographs at the Observatory's headquarters detect tremors worldwide and
information on significant tremors is made public through the media. In case of
severe submarine earthquakes, a tsunami warning would be issued if necessary. In
order to maintain public awareness, tsunami bulletins would be issued to inform the
public about even the smaller scale tsunamis in Hong Kong.
The Hong Kong Time Standard is provided by a caesium beam atomic clock,
which is accurate to within fractions of a microsecond. The Observatory contributes
to the determination of Coordinated Universal Time (UTC) by supplying signals of its
atomic clock to the Bureau International des Poids et Mesures (BIPM) in France. Time
checking services are available to the public through the Observatory's Dial-a-Weather
System, the Internet and local radio stations. The Internet Network Time Service
handled more than 395 million checks in 2006, a rise of 11 per cent compared with
the previous year.