THE ENVIRONMENT
widespread. Landslips and flooding sometimes cause considerably more damage than the winds.
About 80 per cent of the annual rainfall falls between May and September. August is the wettest month and January is the driest.
Severe weather phenomena in Hong Kong include tropical cyclones, strong winter and summer monsoon winds, monsoon troughs and thunderstorms with associated squalls. Waterspouts and hailstorms occur infrequently, while snow and tornadoes are
rare.
304
The Year's Weather
The year 2003 was the fifth warmest since records began in 1884. It was largely due to milder weather in the first few months when there was more sunshine and fewer cold surges than normal. The year was also relatively dry, with rainfall about 12 per cent below normal. It was also notable for having the driest July on record.
Tropical cyclones occurring in the western North Pacific in 2003 were fewer than normal. In Hong Kong, the tropical cyclone season started late in the year. The first tropical cyclone warning signal was issued on July 20, a month later than normal. Only four tropical cyclones, against the mean of six, necessitated the issuance of tropical cyclone warnings locally.
January was sunnier and slightly warmer than usual. It was warmer and drier than usual from February to April. An area of active thunderstorms affected Hong Kong in the evening of April 8 and the Thunderstorm Warning and the Amber Rainstorm Warning were issued for the first time in the year. May was slightly drier than usual and June was wetter than usual.
July was warmer and drier than usual. The monthly mean minimum temperature of 27.6 degrees equalled the record high value set in 1993. The monthly rainfall of 101.8 millimetres, less than one third of the normal figure of 323.5 millimetres, was the lowest on record. Waterspouts and funnel clouds occurred over Hong Kong waters on July 1, 6, 9 and 31. With the approach of Severe Tropical Storm Koni, the first Tropical Cyclone Warning Signal of the year was issued on July 20. The first No. 3 signal and later the first No. 8 Tropical Cyclone Warning Signal of the year were issued on July 23 as Typhoon Imbudo approached Hong Kong.
August was cloudier and wetter than usual. Typhoon Krovanh necessitated the issuance of the No. 3 Strong Wind Signal in Hong Kong. It was wetter than usual again in September. As Typhoon Dujuan skirted the north of Hong Kong about 30 kilometres from the Hong Kong Observatory on September 2, the Increasing Gale or Storm Signal No. 9 was issued for the first time since 1999.
October was sunnier and much drier than normal. November was wetter than normal. December was drier than normal with only a trace of rainfall recorded.
Meteorological Services
Hong Kong Observatory
The Hong Kong Observatory was established in 1883, mainly to provide scientific information for the safe navigation of ships. Since then, it has evolved in line with community needs providing services in and studies on weather forecasting, hydrometeorology, climatology, physical oceanography, aviation and marine