The temperature in urban Hong Kong will plunge to a low of 8 degrees Celsius on Tuesday because of an intense winter monsoon in combination with a cold front.
The official forecast is for a high of only 10 degrees in the urban areas on Tuesday and a couple of degrees lower in the New Territories, according to a weather bulletin from the Hong Kong Observatory.
On Monday afternoon, the temperature across the region was generally 6 to 9 degrees lower than on Sunday and was expected to drop further on Monday night to 10 degrees.
People living in the rural areas were expected to experience colder weather.
Brighter weather will start on Wednesday and the temperature will gradually rise before the weekend, the Observatory said.