The Weather of March 2005

    March 2005 was cooler than normal. The mean temperature of 17.4 degrees was 1.1 degrees below normal. March 2005 was also drier than usual. The monthly rainfall was 52.6 millimetres, which was 14.3 millimetres less than normal. The total rainfall since 1 January amounted to 77.7 millimetres, 44 percent below the normal of 138.3 millimetres for the same period.

    Under the influence of a northeast monsoon, March 2005 started with a spell of rainy, cold and generally overcast weather. The wet and chilly conditions eventually gave way to bright pleasant weather when the clouds dispersed on 5 March. While it remained cool on 6 and 7 March, the long periods of bright sunshine and the weakening of the northeast monsoon brought mild weather to Hong Kong in the ensuing 3 days. Mist and fog affected the territory on 10 and 11 March when a maritime airstream established itself over the south China coast.

    A cold front moved across the south China coast on 12 March, bringing rainy and appreciably colder weather to Hong Kong. The temperature fell from about 22 degrees in the early morning to a minimum of about 10 degrees that night. The temperature dropped further to 9.5 degrees on 13 March, the lowest in the month, and the lowest in March since 1988. While the weather remained cloudy and cold in the following two days, it turned humid and foggy on 16 March when a maritime airstream replaced the northeast monsoon. It was mild with sunny periods the next day. On 18 March, clouds returned and it became cooler with the passage of a cold front through Hong Kong that morning. The clouds dispersed the next day and there were long periods of sunshine on 19 and 20 March. The cloudy condition returned on 21 March as winds freshened from the east.

    Fog patches developed again on the morning of 22 March. Isolated thunderstorms developed during the day and brought over 10 millimetres of rainfall to the eastern part of Hong Kong Island.

    The passage of another cold front on the early morning of 23 March cleared the fog. The rainband associated with the cold front brought more than 15 millimetres of rainfall to parts of Hong Kong Island that evening. Cloudy and cool weather prevailed in Hong Kong in the next three days.

    A humid maritime airstream affected the south China coast again on 27 and 28 March. There was dense fog on 28 March and the visibility fell below 100 metres in the eastern part of the Hong Kong waters that morning. A passenger ferry bound for Nan Sha collided with a barge off the coast of Tsing Yi amid heavy fog, slightly injuring 15 people. In the same morning, a fishing boat collided with a ship south of Hong Kong Island, tossing six people overboard. They were rescued shortly after the accident without sustaining any injury.

    Under the influence of a trough of low pressure, it was cloudy with some rain and fog patches on 29 March. A fresh easterly airstream arrived on the small hours of 30 March, bringing some rain and much cooler weather to Hong Kong in the last two days of the month.

    One tropical cyclone developed over the western North Pacific in March. It moved across the Philippines and then dissipated over the South China Sea. 

    Details of issuance and cancellation of various warnings/signals in the month are summarized in Tables 1.1 to 1.4.  Monthly meteorological figures and departures from normal for March are tabulated in Table 2.