Mainly due to a weaker northeast monsoon over southern China, October was much warmer than usual, the Hong Kong Observatory (HKO) said today.

The monthly mean temperature of 27.3 degrees Celsius, mean maximum temperature of 30.3 degrees Celsius, and mean minimum temperature of 25.4 degrees Celsius, were all the highest on record for October.

There were three very hot days in the month, one of the highest on record for October.

On October 19, with light winds and plenty of sunshine, the maximum temperature recorded in the afternoon was 33.7 degrees, making it the latest very hot day of a year on record.

The month was also much drier than usual with a total rainfall of 11.3mm, only about 9% of the norm. The accumulated rainfall this year up to October was 2,115.6mm, about 10% lower than the norm for the same period.

Five tropical cyclones occurred over the South China Sea and the western North Pacific in October, the HKO added.