May was wetter than usual with 431.5mm of rainfall, 36% above normal. Accumulated rainfall for the year was 733.1mm, 19% above normal.

The month's total bright sunshine duration of 122.2 hours was 31.6 hours below normal.

It was mainly fine and hot on the first day of May. The weather deteriorated with heavy showers and thunderstorms the next two days as Hong Kong came under the influence of a trough of low pressure over the south China coast.

With the trough dissipating, the weather improved and there were some sunny periods on May 6. It was mainly fine and hot over the following six days with a high of 31.5 degrees Celsius on May 8, the highest so far in this year.

A cold front passed on May 13 seeing temperatures fall to 20.5 degrees the following morning.

Meanwhile, Severe Tropical Storm Chanchu entered the South China Sea and intensified into a Typhoon. With the approach of Chanchu, the Hong Kong Observatory issued Standby Signal No 1 on May 15 and the Strong Wind Signal No 3 on May 17, for the first time this year. Chanchu made landfall east of Shantou on May 18.