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 percent 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 8 – 9 and 11 January, the weather of Hong Kong was generally fine and mild during the day on the first sixteen days of the month.  It was also very dry during the day on 13 – 14 January.  With abundant sunshine, the temperature at the Observatory rose to a maximum of 24.8 degrees on the afternoon of 15 January, 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 17 January.  With the moderation of the northeast monsoon, apart from a few light rain patches at first on 18 January, it was generally fine and warm during the day on 18 – 20 January.  Meanwhile, a cold front over the northern part of southern China moved across the coast of Guangdong on the night of 20 January.  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 22 – 23 January.  The weather became very cold on 23 January 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 24 January.  There were also icing reports at Tai Mo Shan on 23 – 24 January.  After a cold morning on 25 January, there were sunny intervals during the day with local temperatures recovering slightly on 25 – 27 January.   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 28 January.   Affected by an easterly airstream and an upper-air disturbance, it was mainly cloudy with a few rain patches on 29 – 30 January. There were also a few mist patches on 30 January.  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 1000 metres on that morning.