More than 200,000 people have been evacuated on an island in Japan's south as life-threatening levels of record rainfall hits.

About 240,000 residents of Japan's southern island of Kyushu have been ordered to evacuate over fears heavy downpours could cause landslides, floods and other natural disasters.

Japan's meteorological agency issued its highest emergency warning level of five this morning following the record levels of rain.

More than 200,000 people have been evacuated on an island in Japan's south as life-threatening levels of record rainfall hits. (Fukuoka) (Kyodo News)

There are fears a natural disaster could hit with record rainfall hammering the island of Kyushu. (Saga) (Kyodo News)

Public broadcaster NHK said one man was killed when his car was washed away in Saga prefecture, where some areas were hit with more than 100mm of rainfall in an hour.

Television footage showed cars with their tyres underwater and people wading knee-deep in flooded streets after several rivers broke their banks.

The evacuated residents are from Fukuoka, Nagasaki and Saga prefectures in northern Kyushu.

The weather agency said parts of northern Kyushu were experiencing torrential rains only seen once in a few decades and assigned the highest alert level of five.