Tropical twister: A tornado developed amid the thunderstorms on September 6 and struck the Hong Kong International Airport at Chek Lap Kok. In a span of just a few minutes, gusts in excess of 60 km an hour overturned a van, injuring one person.

September was drier than usual because tropical cyclones originating from the western Pacific avoided Hong Kong. The monthly rainfall of 167.3 mm was about 44% below the normal figure of 299.7 mm.

The accumulated rainfall for the first nine months of the year was 1,735.9 mm, about 14% below the normal of 2,007.1 mm for the same period.

Associated with Typhoon Songda in the East China Sea, a trough of low pressure formed over the coast of Guangdong and brought thundery showers to the territory on September 6.

Tornado strikes Chek Lap Kok airport

A tornado developed amid the thunderstorms and struck the Hong Kong International Airport at Chek Lap Kok. In a span of just a few minutes, gusts in excess of 60 kilometres an hour overturned a van, injuring one person.

Some cargo was tossed towards a plane while it was being refuelled, damaging a fuel pipe and causing an oil spill.

Over the next three days, unsettled weather persisted as the trough of low pressure continued to linger along the coast.

Under light wind conditions, it was hazy on September 15 and 16 with visibility falling to below 2,000 metres in some parts of the territory.

Showers and thunderstorms returned on September 19 and resulted in more than 70 millimetres of rainfall in parts of Kowloon and Hong Kong Island.

Although it remained sunny on September 21, the weather deteriorated with frequent thunderstorms in the evening when a cold front moved across the south China coast.  The clouds dispersed gradually the next day as the continental airstream behind the cold front dominated over southern China.

Apart from a few showers on September 25 and 30, the weather remained generally fine for the rest of the month.