The Weather of October 2002

    October was cloudier and wetter than usual.  The monthly total bright sunshine duration of 136.8 hours was 58.2 hours below normal, the second lowest for October.  The monthly rainfall of 199.0 millimetres was 37 per cent above the normal amount.  The accumulated rainfall since 1 January amounted to 2402.6 millimetres, 12 per cent higher than the normal figure of 2151.9 millimetres for the same period.

    It was cloudy with some rain on the first day of October.  Clouds thinned out gradually in the next few days as the northeast monsoon established itself over South China.  It became fine on 5 October.

    Clouds and showers returned on 6 October as a cold front crossed the South China coast in the morning.  The drier air behind the cold front dispersed the cloud on 8 October.  Apart from some cloudy intervals brought by an area of low pressure over the South China Sea on 12 and 13 October, fine weather conditions prevailed in the ensuing 8 days.  It was relatively dry during the Chung Yeung Festival on 14 October and a total of 94 cases of hill fire were reported on that day.

    An unstable and moist southeasterly airstream brought showers to Hong Kong on 17 October.  The weather deteriorated further the next morning and heavy rain necessitated the issuance of the Red Rainstorm Warning.  It was the latest Red Rainstorm Warning in a year since the introduction of the Rainstorm Warning System in 1992.  Rain was heaviest in the eastern part of the territory where over 200 millimetres of rainfall was recorded.  There were 13 reports of flooding and 2 workers were slightly injured when they were struck by lightning while working at Mong Kok.  The weather improved quickly in the afternoon and it became fine in the next 2 days.

    A cold front bearing thunderstorms crossed the South China coast on 21 October and brought another episode of heavy rain to Hong Kong.  It became cooler and the temperature fell to 19.6 degrees in the morning of 24 October, the lowest in the month.

    The weather improved on 25 October with long periods of sunshine for 2 days.  Winds strengthened from the east on 27 October, bringing rain patches to Hong Kong in the next 3 days.  Rain became more or less continuous as another cold front arrived at the South China coast on 30 October.  It was overcast with rain patches on the last day of the month.

    A total of 3 tropical cyclones occurred in 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 1.4.  Monthly meteorological figures and departures from normal for October are tabulated in Table 2.