The rain comes during an unseasonably dry start to Australian spring, which began in September.

Thousands of people were killed after two dams above Derna broke on Sept 10 during a powerful storm, bringing down residential blocks lining a usually dry river bed as people slept.

The weather bureau has issued the highest 'black' rainstorm warning and said more than 200mm of rainfall was recorded on Hong Kong's main island, Kowloon and the northeastern part of the city's New Territories.

China continues to experience the main flooding period, hit by heavy rain, floods and typhoons saturating the soil in some mountainous northern and northeastern areas, reports say.

China was inundated with heavy rain and flooding in northern and northeastern regions in recent weeks brought by storms from Typhoons Doksuri and Khanun.

Unusually heavy rain and melting glaciers have brought deadly flash floods to the mountains of India, Pakistan and Nepal over the past year or two, with government officials increasingly blaming climate change.

The country has had an unusually wet and rainy season with massive flooding in its northern and northeastern provinces, such as in Hebei where more than 1.5 million people had to be evacuated in early August.

The growing frequency and intensity of severe weather across the US is symptomatic of global, human-driven climate change, climate scientists say.

Japan is the latest country to be hit by unusually heavy rain in various parts of the world in recent days that has raised new fears of the pace of climate change.

Over the past few weeks, heavy downpours in southern, central and northern provinces and regions have displaced thousands, destroyed bridges and washed away cars and homes.

Large swathes of the South Asian country were submerged due to monsoon rains and melting glaciers, a phenomenon linked to climate change that damaged crops and infrastructure and killed at least 1,700 people.

Muddy waters flowed through the streets washing over the roofs of parked cars, submerging some stores and forcing locals to flee to the top stories of their homes.