With haze occurring on most days in January, the number of hours of reduced visibility observed at Hong Kong International Airport reached an all-time high of 484 hours (about 65% of the time) for the month.

January was also drier than normal, with the monthly rainfall of 5.9mm being 17.5mm below normal.

An intense surge of the winter monsoon brought fine, dry and very cold weather on New Year's Day, with the temperature hitting the third record low of 6.4 degrees.

While remaining cold, it turned cloudy on the next two days. With the weakening of the winter monsoon, the weather turned fine on the 6th and prevailed until the 12th. There were also long periods of haze from January 4 to 12.

Cold surge

Another intense cold surge arrived on January 13, bringing cloudy and rainy weather, with temperatures falling to about 10 degrees.

The temperature dropped to seven degrees the next morning. Ice pellets and icicles were reported on Tai Mo Shan where the temperature fell to -2.1 degrees. Clouds dispersed during the day and the weather remained fine and cold on the next two days.

As local winds moderated, it became hazy again in the following three days. Visibility at the airport fell below 3,000 metres on January 19.

It became cloudy with some mist patches on the 20th when a replenishment of the winter monsoon arrived at the south China coast. For the next two days it was mainly cloudy with some light rain patches in the morning.

Under the influence of a maritime airstream, it was humid with mist and fog from January 23 to 30. On the night of the 25th, two cargo ships collided near Lei Yue Mun in thick fog.