ENG-1977 — Page 265

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THE ENVIRONMENT

January was much colder than usual. There were 18 days with minimum tempera- tures below 10°C and the month was the coldest January since 1934. On the morning of January 5, the air temperature fell to a minimum of 6.2°C, the lowest recorded in the year. Because of the cold weather, 11 people were reported to have died in the urban areas. Farmers in the New Territories reported heavy losses of piglets and chickens. The rainfall for both months was much below average. Conditions were very dry in February and, although many fire danger warnings were issued, numerous fires broke out both in buildings and in forest areas. On the last three days of February, a humid airstream from the Pacific caused widespread fog in coastal areas.

Rainfall was very much below average in March and April. Both months were sunnier and warmer than usual. The mean relative humidity of 73 per cent in March was the lowest on record for March, while the mean temperatures in April were the highest on record for April. Persistent and widespread fog was reported in coastal areas on March 2 and a triple-decker ferry sank after colliding with a hydrofoil near Hei Ling Chau. Heavy showers on April 28 brought a welcome relief and enabled farmers to start transplanting some crops.

The dry conditions came to an end in the middle of May, which was the first month since August, 1976, with above average rainfall. The first half of the month was fine and sunny, but an active trough of low pressure remained close to Hong Kong for the remainder of the month, which was cloudy with frequent heavy showers and scattered thunderstorms.

Rainfall was below average in June, July and August and these months were much hotter than usual. On the afternoon of August 24, the air temperature rose to a maximum of 34.9°C-the highest recorded in the year. The first tropical cyclone of the year for which signals were displayed in Hong Kong was Tropical Storm Ruth. It passed about 320 kilometres to the east of Hong Kong on June 16 and had little effect on local weather. In July, signals were hoisted for three tropical cyclones and two of them caused heavy squally showers and strong winds in Hong Kong. Signals also were hoisted for Tropical Storm Amy in August. However, when it was about 400 kilometres east of Hong Kong late on August 21, it recurved into the Taiwan Strait and left Hong Kong unaffected.

Rainfall in September was about 50 per cent above average. Five tropical cyclones developed over the western North Pacific and the South China Sea during the month and local signals were hoisted for three of them. Tropical Storm Carla, the wettest tropical cyclone of the year, passed about 380 kilometres south of Hong Kong on September 3 and winds in Hong Kong were strong easterly from the evening until the following afternoon. Between September 4 and 6, as Carla moved over Vietnam, an active rainband stayed near Hong Kong and resulted in 268.4 mm of rainfall at the Royal Observatory. Typhoon Dinah stayed over the northern part of the South China Sea from September 16 to 22 and the standby signal remained hoisted for a record 124 hours and 40 minutes. On September 24, Severe Tropical Storm Freda moved rapidly across the South China Sea and passed within 128 kilometres of Hong Kong. It was the only tropical cyclone for which gale or storm signals were hoisted during the year. Although no significant damage was reported, all public transport services and air traffic were disrupted and 37 casualties were reported.