Temperature plunged below the freezing point in some parts of New Territories this morning, with farmers reporting large scale damages to their crops.

The mercury in Ta Kwu Ling touched 0.9 degrees - the lowest in 33 years since its record began.

The observatory pointed to a phenomenon called "radiative cooling" for the plunge, while predicting temperatures to get warmer in the next few days before a reverse at the beginning of next week.

Radiation cooling is a maximum cooling of the ground which occurs under clear skies, light winds and dry conditions. In winter, a large temperature difference sometimes exists between the urban area and the New Territories.

According to the Hong Kong Observatory, the winter monsoon will moderate slightly in the next couple of days, bringing warmer weather ranging from 12 to 20 degrees from Thursday to Saturday, but still cold in the morning over inland areas.

While another surge of the winter monsoon will affect Hong Kong early next week, with the weather becoming cold again, along with some rain in the middle and latter parts of next week.
https://www.sott.net/article/447181-Hong-Kong-records-coldest-temperature-in-33-years-large-scale-crop-damage-reported