The Weather of March 2003

    March 2003 was warmer and drier than usual.  The mean temperature of 19.0 degrees was 0.5 degree above normal.  The monthly rainfall of 38.6 millimetres was some 40 per cent less than the normal figure of 66.9 millimetres.  The accumulated rainfall since the beginning of the year was 75.4 millimetres, about half of the normal figure of 138.3 millimetres for the same period.

    Under the influence of the northeast monsoon, the weather was fine and warm on the first day of March 2003.  Winds freshened from the east on 2 March and it turned cloudy with mist and light rain patches for 2 days.  As the easterlies further strengthened on 4 March, it became cooler with moderate rain for another 2 days.  A cold front crossed the South China coast in the morning of 6 March, bringing more rain and overcast conditions to Hong Kong.  The temperature fell by some 8 degrees during the day to a minimum of about 13 degrees in the evening.  Under the influence of the cold and dry air behind the cold front, rain ceased on 7 March and the temperature dropped further to 11.5 degrees, the lowest in the month.  It became brighter on the next day, albeit still quite chilly.  When winds strengthened from the east again on 9 March, rainy conditions returned.  The rain eventually ceased as a dry airstream reached Hong Kong in the afternoon of 10 March.  The weather became fine and warm for the next 4 days.

    The dry air was replaced by a moist airstream on 14 March and it became cloudy. There were mist and fog patches in the mornings of the ensuing 5 days.  The weather turned mainly fine from 16 March and the temperature rose to 26.6 degrees on 17 March.

    Another cold front crossed the South China coast in the morning of 18 March. It brought a spell of cool, rainy and misty weather to Hong Kong for 7 days.  About 10 millimetres of rainfall were recorded at Lantau and Hong Kong Island on 20 March.

    A warm maritime airstream reached Hong Kong on 25 March and brought fine weather with morning mist to the territory for 3 day.  Winds freshened from the east again on 28 March and cloudy weather returned with light rain patches.  There were also fog patches in the morning.  Cloudy conditions persisted for the next 3 days with mist in the mornings.  With more sunshine on the last day of the month, the temperature rose to 26.7 degrees, the highest in the month.

    There was no tropical cyclone over the South China Sea and the western North Pacific in the month.

    Details of issuance and cancellation of various warnings/signals in the month are summarized in Tables 1.1 to 1.3.  Monthly meteorological figures and departures from normal of March are tabulated in Table 2.