July was marked by heavy rain and severe thunderstorms, the Observatory says. The total rainfall of 569.2mm in the month was 245.7mm above the normal figure.

The accumulated rainfall since January 1 was 1,771.5mm - 35% more than the usual 1,316 mm for the same period.

Apart from some isolated showers, it was fine and hot in the first four days of the month. Under the influence of the southwest monsoon, periods of sunshine and some showers were seen from July 5 to 10.

Affected by a weak trough of low pressure along the south China coast, there were scattered showers and squally thunderstorms on July 11.

When Severe Tropical Storm Bilis moved near Taiwan on July 13, it was hot in Hong Kong and the maximum temperature shot up to 34 degrees, the highest in the month. The outer rainbands of Bilis brought scattered squally showers to Hong Kong on July 14.

Hourly rainfall breaks record

Showery weather continued on July 15 as an active southwest monsoon set in. In the early morning of July 16, the weather deteriorated with heavy downpours and squally thunderstorms. More than 150mm of rainfall was recorded in Hong Kong Island, Kowloon, Cheung Chau and Tseung Kwan O, resulting in the issuing of a black rainstorm warning.

Between 2am and 3am, a record-breaking 115.1mm of rainfall was registered at the Hong Kong Observatory Headquarters, breaking the previous f hourly rainfall record of 109.9mm recorded from 6am to 7am on May 8, 1992.

The weather stayed cloudy with a few showers on July 17.

Sunny weather returned on July 18 when a ridge of high pressure dominated over southeastern China. Apart from a few isolated showers, fine and hot weather prevailed in the next five days.

Hail reported at Sai Kung

Under the influence of the subsiding air ahead of Typhoon Kaemi, it was hot and hazy on July 24 and 25. The high daytime temperatures triggered the development of severe squally thunderstorms in the afternoon of July 24. Hail was reported at Sai Kung during the thunderstorms.

The weather became cloudy with some showers on July 26, affected by Kaemi's rainbands. Hong Kong came under the influence of an active southwesterly airstream on July 27. It was rainy with scattered squally thunderstorms. Unsettled weather persisted in the following two days.

Local weather improved on July 30 under the influence of a ridge of high pressure over southeastern China. It was sunny on the last day of the month.

Four tropical cyclones occurred in the western North Pacific and the South China Sea in the month.