With the northeast monsoon over the south China coast generally weaker than normal for most of the time in the month, January 2024 was overall warmer than usual in Hong Kong despite a very cold episode in the latter part of the month. The monthly mean maximum temperature of 20.5 degrees, monthly mean temperature of 17.9 degrees and monthly mean minimum temperature of 15.9 degrees were 1.8 degrees, 1.4 degrees and 1.3 degrees above their corresponding normals and respectively the sixth, one of the sixth and one of the seventh highest on record for January. The month was also drier than usual with a total rainfall of 6.7 millimetres, about 20 per cent of the normal figure of 33.2 millimetres.

     Under the influence of the northeast monsoon and the subsequent weak replenishments, apart from a few light rain patches on January 8, 9 and 11, the weather of Hong Kong was generally fine and mild during the day on the first 16 days of the month. It was also very dry during the day on January 13 and 14. With abundant sunshine, the temperature at the Observatory rose to a maximum of 24.8 degrees on the afternoon of January 15, the highest of the month.

     Affected by a cloud band over the coast of Guangdong, it was mainly cloudy with a few rain patches on January 17. With the moderation of the northeast monsoon, apart from a few light rain patches at first on January 18, it was generally fine and warm during the day from January 18 to 20. Meanwhile, a cold front over the northern part of southern China moved across the coast of Guangdong on the night of January 20. Locally, winds strengthened gradually from the north and temperatures fell appreciably with sunny intervals the next day. Under the influence of the associated intense winter monsoon and with a broad band of clouds covering southern China, there were a few rain patches with local temperatures falling further on January 22 and 23. The weather became very cold on January 23 with temperatures at the Observatory dropping to a minimum of 6.3 degrees on that morning, the lowest of the month. Moreover, the temperature at Tai Mo Shan fell to a minimum of -2.9 degrees on that day. The weather of Hong Kong remained mainly cloudy and very cold on the morning of January 24. There were also icing reports at Tai Mo Shan on January 23 and 24. After a cold morning on January 25, there were sunny intervals during the day with local temperatures recovering slightly from January 25 to 27. Under the influence of a weak replenishment of the northeast monsoon, local weather turned cold again with a few rain patches on the morning of January 28. Affected by an easterly airstream and an upper-air disturbance, it was mainly cloudy with a few rain patches on January 29 and 30. There were also a few mist patches on January 30. Under the influence of a humid maritime airstream, it was mainly cloudy and foggy with light rain patches on the last day of the month. The visibility in the harbour once fell below 1 000 metres on that morning.

     There was no tropical cyclone over the South China Sea and the western North Pacific in January 2024.

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

Ends/Friday, February 2, 2024
Issued at HKT 16:00

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