The Weather of January 2000

    January was warmer than usual. The monthly mean temperature was 17.0 degrees, 1.2 degrees higher than normal. It was also wet with the monthly rainfall of 70.3 millimetres, the ninth highest for January. However, most of the month's rainfall was recorded during a three-day rainy episode from 23 to 25 January.

    The new year started fine and dry with haze in the western areas on the first two days. The weather remained mainly fine and sunny the next few days apart from some cloudy periods on 4 and 5 January.

    It was misty on the morning of 6 January with visibility in the harbour reduced to 2 000 metres. Winds freshened from the east early the next day as a weak cold front crossed the coast of Guangdong. The weather became cloudy to overcast with reduced visibility in the morning. Winds subsided on 8 January and it became sunny.

    The weather turned cloudy again on 9 January. There were some light rain patches the next evening and cloudy weather with light rain patches continued the next few days. Temperatures reached 24.0 degrees on 12 January, the highest in the month. It was misty again on the morning of 13 January. Another weak cold front crossed the south China coast later that day clearing the mist. Rain eased off on 14 January but the weather remained mainly cloudy.

    A cold front crossed the coast of Guangdong on 16 January. It became overcast on 18 January with winds strengthening from the north. Under the influence of this colder airstream, temperatures dropped to 9.9 degrees on the morning of 19 January as clouds dispersed and winds moderated. Sunny weather persisted the next day.

    Winds strengthened from the east on the evening of 20 January and cloudy weather returned. Winds moderated on 22 January. Periods of rain, heavy at times, affected Hong Kong under the influence of a moist easterly airstream on 23 and 24 January.

    The northeast monsoon over China intensified further later on the evening of 24 January with strengthening northerly winds. Under the influence of this drier airstream, rain eased off on 26 January. The cold airstream from the north also brought the temperature down to 7.2 degrees on the morning of 27 January, the lowest in the month. Icing and frost were reported on Tai Mo Shan, where a minimum temperature of -2.5 degrees was recorded that morning. Frost was again reported in the northern part of the New Territories the following day.

    Long sunny periods developed on 27 January. It remained mainly fine and dry during the next few days. The weather became cloudy with light rain patches on 31 January and winds were occasionally strong offshore in the evening.

    No tropical cyclone occurred in the western North Pacific and the South China Sea in the month.

    During the month, one aircraft was diverted due to adverse weather.