THE ENVIRONMENT
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May was wetter than normal and rainfall amounted to 468.2 mm, which was 57 per cent above average. More than one third of the rain fell on May 30 when widespread thunderstorms and heavy showers caused serious flooding and numerous landslips in various parts of Hong Kong.
The temperature and rainfall in June were normal. However, squally thunderstorms on June 3 caused the collapse of a temporary steel structure at a construction site in Sheung Shui; one person was killed. Widespread thunderstorms and torrential rain on June 16 caused serious flooding and landslips in many places, with the worst-hit area being Sai Tau Tsuen in Kowloon City. A waterspout was sighted over the West Lamma Channel at about 2.30 p.m. on June 24. Tropical cyclone warning signals were displayed for the first time in 1984 during the approach of Severe Tropical Storm Wynne which, however, caused only slight damage in Hong Kong.
July had the distinction of being the sunniest month ever in Hong Kong since record keeping began in 1884. It was also the fourth driest July. Bright sunshine totalled 301.4 hours, and rainfall amounted to 125.9 mm. Tropical cyclone warning signals were displayed during the approach of Severe Tropical Storm Betty, which caused minor damage to crops.
August was less sunny than average with only 162.7 hours of bright sunshine, 43.3 hours fewer than normal. Two spells of widespread thundery showers caused landslips and flooding in many places in the first half of the month and tropical cyclone warning signals were displayed on two occasions, during the approach of Severe Tropical Storm Gerald and Severe Tropical Storm June. Neither caused severe damage in Hong Kong.
September was drier than usual with a total rainfall of 211.3 mm, which was about 34 per cent below normal. More than half of the rainfall fell on September 1 and 2 and was caused by a trough of low pressure lying close to the south China coast. A Gurkha soldier was killed and three others were injured by lightning on September 18 while they were on an exercise near Pat Sin Range. Tropical cyclone warning signals were hoisted during the approach of Typhoon Ike, which caused only slight damage to Hong Kong.
Fine weather prevailed during October. However, the total rainfall of 167.1 mm was 38 per cent above normal. Most of the rain was recorded on October 10 and 11 when heavy showers occurred. An hourly rainfall of 67.2 mm was recorded at the Royal Observatory from 11 p.m. to midnight on October 10. This amount was the second highest on record for October.
The total rainfall recorded in November was only 4.5 mm, representing a mere 13 per cent of the normal amount of 34.7 mm. Under the influence of the winter monsoon, the latter part of the month was rather dry and the daily mean relative humidity from November 18 to 30 was 70 per cent or less every day.
December was cloudier than usual. Bright sunshine amounted to only 111.9 hours, which was 67.4 hours below normal. Temperatures fell as the winter monsoon intensified and a minimum temperature of 7.7°C was recorded at the Royal Observatory on December 29. Minimum temperatures of -2.0°C and 1.1°C were recorded at Tai Mo Shan and Tate's Cairn respectively on the same day.
The Royal Observatory
The Royal Observatory was established in 1883 mainly to provide scientific information for the safe navigation of ships. In the 100 years since then, the observatory has evolved in line with the changing needs of the community. In 1984, its work covered a wide range of scientific disciplines.