A sunny and dry January

     The weather of the first month in 2013 was characterised by plenty of sunshine and dry conditions which were attributed to the prevalence of the relatively dry winter monsoon for most of the month. The total duration of sunshine in January 2013 was 184.0 hours, 41.0 hours above the normal figure of 143.0 hours. The total rainfall of the month was only 3.4 millimetres, 21.3 millimetres below the normal figure of 24.7 millimetres. The month was also warmer than usual. The monthly mean temperature of 16.7 degrees was 0.4 degrees above the normal figure of 16.3 degrees.

     Under the influence of the winter monsoon, it was cold and very dry in Hong Kong on the first day of the month. The temperature at the Hong Kong Observatory fell to a minimum of 10.8 degrees in the morning, the lowest of the month. With the winds veering to the east, temperatures over most parts of the territory rebounded on January 2. A replenishment of the winter monsoon arrived at the south China coastal areas on January 3, bringing cooler weather to Hong Kong. The weather turned cloudy and cold on January 4. Dominated by the dry winter monsoon, local weather was generally fine and cool with some haze for the ensuing five days.

     An extensive cloud band over southern China brought generally cloudy weather to the territory on January 10. There were sunny periods with haze for the next two days. Affected by a dry continental airstream, it was sunny on January 13 and 14. A cloud band over the south China coastal areas brought cloudy weather to Hong Kong on January 15. With the clouds thinning out, it turned fine and dry the next day.

     A replenishment of the winter monsoon reached the south China coast on January 17. Locally, it was fine and dry with winds freshening from the north in the afternoon. Temperatures over most parts of the territory were 2 to 3 degrees lower than those of the previous day. With the prevalence of the winter monsoon, it remained fine and dry on January 18 and 19.

     Under the influence of a relatively mild easterly airstream, local weather became warmer on January 20 and the ensuing two days. The temperature at the Observatory rose to a maximum of 25.6 degrees on January 22, the highest of the month. A weak replenishment of the winter monsoon brought slightly cooler weather with relatively low visibility from January 23 to 25. Affected by a rain band over the south China coastal areas, there were a few mist and rain patches on the next two days. With the return of the dry northeast monsoon, local weather became generally fine and dry on January 28 and 29. Under the influence of a fresh easterly airstream, it was mainly fine and mild on the last two days of the month.

     One tropical cyclone occurred over the South China Sea and the western North Pacific in the month.

     Details of the issuance and cancellation of various warnings/signals in the month are summarised in Table 1. Monthly meteorological figures and departures from normal of January are tabulated in Table 2.

Ends/Monday, February 4, 2013
Issued at HKT 18:15