Unusual twist: A funnel cloud formed near Hong Kong International Airport on August 24.

Hong Kong experienced its second-wettest August last month since records began in 1884, with the total rainfall of 971.3mm more than doubling the normal figure of 391.4mm.

The two-day deluge of 546.2mm on August 19 and 20 also set a new record for the month.

Accumulated rainfall since January 1 was 2,844.2mm, about 67% more than the normal figure of 1,707.4mm and was second only to the rainfall recorded in the same period in 1997.

Under the influence of Typhoon Matsa to the east of Taiwan, the maximum temperature reached 33.5 degrees on August 6, the month's highest.

Latest typhoon season on record

Typhoon season started late in Hong Kong this year - the latest on record. Tropical Storm Sanvu entered the South China Sea August 12 and the No.1 Standby Signal, the first of the year, was issued. Locally, the weather became hot and hazy with thunderstorms. Sanvu intensified into a Severe Tropical Storm that night and made landfall near Shantou the next day.

As the trough of low pressure edged towards the south China coast, there were long periods of rain on August 19. More than 200mm was generally recorded over Hong Kong that day. In heavy rain and violent squalls, a century-old banyan tree in Central collapsed, blocking Lower Albert Road.

The weather deteriorated further on August 20 when southwesterly winds strengthened. The Amber Rainstorm Warning, Strong Monsoon Signal, Landslip Warning, Thunderstorm Warning and the Special Announcement on Flooding in the Northern New Territories were all put in force.

Fatal landslip

Widespread and persistent heavy rain brought more than 300mm to most areas and resulted in serious flooding and landslides. One man was killed in a landslip in Fu Yung Shan Tusen in Tsuen Wan. About 150 tourists at Po Lin Monastery on Lantau Island were stranded after landslides blocked South Lantau Road. In Tuen Mun, 15 people trapped by metre-deep flood water were rescued by firemen.

The weather remained unstable with scattered heavy showers on August 21. During the downpour from August 19 to 21, there were more than 30 reports of flooding and more than 100 reports of landslides.

With the trough of low pressure moving to the north, the weather was mainly fine August 22 and 23. But thundery showers returned August 24 as the trough drifted back to the south China coast. A funnel cloud was also spotted near Hong Kong International Airport that morning.