The Hong Kong Observatory (HKO) said today that 2025 is the city’s sixth warmest year on record, while globally it is expected to rank as the second or third warmest, according to a preliminary assessment from the World Meteorological Organization.

All 12 months last year were warmer than usual in the city, with the monthly mean temperature in October setting a new record, the HKO said.

The annual mean maximum temperature of 27.1 degrees Celsius and the annual mean minimum temperature of 22.4 degrees Celsius were the fifth highest and sixth highest respectively since records began in 1884.

The lowest temperature recorded at the HKO last year was 10.6 degrees Celsius on January 27. There was a total of six cold days, 9.2 days less than the normal for the 1991-2020 period.

It was also the first time that no cold weather warning was in force in November or December since the Cold Weather Warning System began operation in 1999.

In the first half of 2025, the accumulated rainfall was 444.4mm - the fifth lowest amount on record for the period. However, from July to September, periods of heavy rain brought the total rainfall for the year to 2,558.7mm, about 5% more than the 1991-2020 normal of 2,431.2mm.

The concentrated rainfall in the July to September span contributed more than 80% of the total annual rainfall. Sixteen Red Rainstorm Warning Signals and five Black Rainstorm Warning Signals were issued, the highest annual numbers on record.

The HKO issued 14 tropical cyclone warning signals in 2025, more than double the annual long-term average of six. It was the highest annual number since 1946.

The Hurricane Signal No. 10 was issued twice in 2025 - during Typhoon Wipha in July and Super Typhoon Ragasa in September - tying the previous record in 1964, the HKO  added.