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January 2012 was colder than usual under the dominance of the winter monsoon. The mean temperature of the month was 15.1 degrees, 1.2 degrees below the normal figure of 16.3 degrees. The month was also wetter and gloomier than usual. The total monthly rainfall of 42.1 millimetres was 17.4mm above normal. The total duration of bright sunshine in the month was 86.0 hours, a deficit of 40 per cent against the normal figure of 143.0 hours.
Under the influence of a continental airstream, the weather in Hong Kong was mainly fine and dry for the first three days of the month. An intense surge of the winter monsoon reached the coastal areas of Guangdong during the night on January 3 and brought cold weather with rain patches to the territory from January 4 to 6. The weather remained cloudy and cool on January 7. With clouds thinning out, it became generally fine with some haze for the ensuing three days.
Affected by a broad rain-bearing cloud band over southern China, local weather turned rainy from January 11 to 13. While the winter monsoon moderated in the next two days, the rain continued with fog and mist. The visibility at Waglan Island once fell to 100 metres in the morning of January 15. Meanwhile, a cold front formed over inland Guangdong on January 15 and moved across the coastal areas the next morning, bringing cooler weather to Hong Kong on January 16.
With the prevalence of a relatively mild easterly airstream, there was plenty of sunshine and the temperature rose gradually from January 17 to 19. The temperature at the Observatory reached a maximum of 22.4 degrees on January 19, the highest level of the month. Local weather became cloudy with some coastal fog when the easterly airstream freshened for the next two days.
An intense winter monsoon reached the south China coast in the morning of January 22 and the weather became progressively colder with rain patches from January 22 to 26. The temperature at the Observatory fell to a minimum of 7.4 degrees in the morning of January 25, the lowest during the Lunar New Year holidays since 1996. With the winter monsoon over the south China coastal areas being generally replaced by a humid easterly airstream, local weather was misty with temperatures rising gradually on January 27 and 28. Affected by a weak replenishment of the winter monsoon, the weather became slightly cooler for the next two days. A dry continental airstream brought mainly fine and dry weather to the territory on the last day of the month.
There was no tropical cyclone over the South China Sea and the western North Pacific in the month.
Details of the issuance and cancellation of various warnings and signals in the month are summarised in Table 1. Monthly meteorological figures and departures from normal in January are tabulated in Table 2.
Ends/Thursday, February 2, 2012
Issued at HKT 18:49
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