Hong Kong is set for a significant cool-down as a strong northeast monsoon sweeps in, with the Hong Kong Observatory issuing a Special Weather Tip early this morning (18 Nov).
The cold front is expected to cross the Guangdong coast around midnight tonight, ushering in markedly cooler weather across the city. Temperatures will drop noticeably today, with urban areas falling to around 15°C by night and parts of the New Territories a degree or two lower. Some areas in the New Territories are likely to feel cold.
Wednesday (19 Nov) and Thursday (20 Nov) will be the coldest days, with minimum temperatures in built-up areas dipping to about 14°C. The strong northeasterly winds will make it feel even chillier due to a pronounced wind-chill effect.
The Observatory forecasts mainly cloudy skies today with a few light rain patches. Morning temperatures will hover around 21°C before falling steadily through the day. Moderate to fresh northerly winds are expected, occasionally strong offshore and on high ground.
Looking ahead, the weather will gradually improve later in the week as an extensive cloud band over southern China thins out and the monsoon eases. Sunshine will return, but mornings will remain cool, and the air will become very dry. By the weekend and early next week, day-night temperature differences will be large, with daytime highs climbing back to 24–25°C while early-morning lows stay around 16–19°C. Relative humidity is forecast to drop as low as 30–35% on several days, signalling very dry conditions.
The Observatory and the Senior Citizen Home Safety Association have urged the public, especially the elderly and those with chronic illnesses, to stay warm, wear appropriate clothing, and monitor vulnerable family members. Residents are also reminded to prepare for the sudden change and, where necessary, make use of personal safety alert systems.
The sharp cooling arrives just ahead of the traditional Chinese solar term “Light Snow” (小雪) on Saturday (22 Nov), which this year is expected to be ironically very dry rather than wintry.