A hot weather warning took effect at 6.45am on October 21, with the Hong Kong Observatory forecasting a high of about 33C in the city and temperatures 2–3C higher in parts of the New Territories.
An earlier district forecast put Sheung Shui at 37C at 2pm, Tin Shui Wai at 36C and Yuen Long at 35C, temperatures the Observatory described as extreme heat.
The day was expected to be generally fine and dry, with low visibility in the morning and minimum relative humidity around 55%.
If the Observatory’s headquarters recorded at least 33.0C that day, October 21 would become the year’s latest hot-weather day, surpassing the existing record of October 19, 2024, when the headquarters recorded 33.6C.
Hot, dry conditions were forecast to continue. The Observatory said sinking air around a typhoon would bring sunny, hot and very dry weather to South China later in the week; minimum relative humidity in Hong Kong was forecast to fall to around 35% on October 23.