The Hong Kong Observatory said the month was exceptionally warm in the finance hub due to "a stronger than normal upper-air anticyclone covering southern China", adding that cooler air from the north only reached the coast of southern China later in October.

"The monthly mean temperature of 27.4 degrees (Celsius) and monthly mean minimum temperature of 25.6 degrees were both the highest on record for October," the Observatory said.

The monthly mean maximum temperature of 29.9C was the second highest on record, it added.

Hong Kong also logged the highest number of "very hot days" -- when the mercury climbed to 33.0C or above -- since records began in 1884, the weather agency said.

There was also a record of seven hot nights in total during the month, and the minimum temperature recorded on October 19 was 28.2C, making it the latest hot night of a year on record.

The weather service said in early October that the city has experienced one of its most severe typhoon seasons, with at least 12 tropical cyclone warnings issued this year -- a record number since 1946.

In 2025, Britain, Spain, Japan and South Korea all endured their hottest summers, according to their weather agencies.

The United Nations said 2024 was the hottest year recorded, with Hong Kong also logging the city's hottest year since records began.