Hong Kong weather

Wet July to make way for even wetter August, Hong Kong Observatory says

Last month saw 50 per cent more rainfall than the average for July, with more clouds and less sunshine

PUBLISHED : Wednesday, 02 August, 2017, 3:31pm
UPDATED : Wednesday, 02 August, 2017, 9:51pm

Hongkongers were forced to break out their umbrellas more than usual last month, with tropical storms bringing in 50 per cent more rain than usual.

The city got 570mm of rain compared with the average monthly rainfall of 376.5mm for July, according to the Hong Kong Observatory.

There was also less blue sky last month, with 10 per cent more cloud than average and 49.1 fewer bright sunshine hours, according to the city’s official forecaster.

Mike Cheung Sze-yuen, an experimental officer at the Observatory, said the wet and cloudy weather was due to a low-pressure trough early in the month and cyclones later on.

But he said the weather was still within a normal range and was “not too extreme”, adding that the highest rainfall for July on record was in 1994, when the city got 1,147.2mm across the month.

The wet weather is likely to continue – and potentially worsen – in August, which is typically more rainy than July, Cheung said.

“In August, the rainfall should be more than July,” he said, noting that the average amount of rain for August, calculated from records going back to 1981, was 472mm. “Usually this is the rainy season in Hong Kong.”

The gloomy July continued what had already been a wet year, with an accumulated 1,759.8mm of rainfall recorded in the first seven months – nearly 20 per cent higher than the average figure for the same period.

Unusually high July rainfall sparks flood risk concerns in Hong Kong’s rural areas

The month got off to a rainy start thanks to a southwest monsoon, which brought heavy downpours to the New Territories, according to the Observatory.

Towards the middle of July, tropical cyclone Talas brought outbreaks of heavy rain and squally thunderstorms, prompting rainstorm warnings.

Tropical cyclones Roke and Sonca brought showers, while another pair of tropical cyclones, Haitang and Nesat, ushered in cloudy skies and isolated showers last weekend.

In total, there were eight tropical cyclones over the South China Sea and western North Pacific in July.