234
GEOGRAPHY AND CLIMATE
structure of rain clouds associated with the various synoptic systems which affect the Colony was also studied by means of the newly installed weather radar.
The problem of air pollution by sulphur dioxide continued to be investigated and the effect of industrial smoke on the reduction of visibility in Hong Kong harbour was also examined. The observatory co-operated with several overseas scientific institutes in various special studies in seismology, radio-activity, marine climatology and atmospheric chemistry.
THE YEAR'S WEATHER
Although the weather during the year showed few departures from normal, the rainfall during the first seven months was only 1,570.6 mm (61.83 inches) which was the seventh lowest on record. The accumulated total for the 12 months ending July 31 was the lowest ever recorded for this period and it appeared at the time that Hong Kong might face another severe drought like that of 1963. However, heavy rain associated with three tropical cyclones in August filled most of the reservoirs.
January and February were colder than usual with several intense surges affecting the Colony. On January 15, the air temperature fell to 4.6°C at the Royal Observatory and 1.0°C at Ngong Ping in Lantau. There was frost in many places in the New Territories and on hill tops, and a thin layer of ice formed in the evaporation pans at King's Park for the first time. On February 2 sleet was reported at Cape Collinson. In between the cold spells warm moist air from the Pacific Ocean reached the Colony causing fog in the harbour area. The strong monsoon signal, the Black Ball, was hoisted on January 15 and February 6 and 14 to give warning of strong winds associated with the winter monsoon.
The sea temperatures in March were lower than normal and this resulted in two long spells of foggy weather. Both air and sea traffic were seriously interrupted during these spells and two ocean freighters were involved in a collision off Tathong Point on March 29.
April was wet but sunny. A thunderstorm on the first was accom- panied by hail-with stones up to half an inch in diameter-over
Page 315Page 316
No comments yet.
Private notes are available after approval.