The Hong Kong Observatory said its heat warning remained in force on National Day, with the urban area expected to reach about 34°C. Temperatures in the New Territories could be 1–2°C higher than in the urban area, and some areas could become extremely hot.
The maximum UV index was forecast at about 9, classed as very high. In a special weather reminder issued at 6.45am, the Observatory advised people to drink enough water, rest or seek help if they felt unwell, and seek medical attention promptly when necessary.
The day was expected to start generally sunny before becoming cloudier, with a few showers later and thunderstorms possible locally. Showers were forecast to be more frequent on October 2 and 3, when the urban high should be around 31°C.
Conditions are expected to become brighter and cooler from early to midweek, although a few showers may remain at first. Morning temperatures are forecast to fall to about 24–25°C as the weather improves.