October 2026 was Hong Kong’s warmest October in the recorded series, with records set for all three monthly temperature averages, the Hong Kong Observatory said.
The mean maximum temperature was 30.5°C, 2.4°C above normal. The mean temperature was 27.6°C and the mean minimum was 25.8°C, both 1.9°C above normal. Each was the highest recorded for October.
The Observatory attributed the unusual warmth mainly to a weaker-than-normal northeast monsoon and a stronger-than-normal upper-air anticyclone affecting South China. It said the conditions came against a background of climate warming and a super El Niño that might continue until early 2027.
Rainfall totalled 81.0mm, about 67% of the normal 120.3mm. The month was still wet in places early on: on October 2 and 3, many areas recorded more than 50mm, while parts of Kowloon, Sha Tin and Sai Kung received more than 100mm.
The month’s highest temperature, 33.6°C, came on October 1. On October 6, the temperature fell to 23.3°C, the month’s low and the lowest recorded since autumn began that year.
On October 23, the Observatory recorded 32.3°C, making it the hottest Frost’s Descent, a traditional solar term, on record.