On Thursday, the torrential rain flooded roads across the prefecture, causing all transport to come to a standstill and grounding flights.
According to Satoshi Ebihara, an official in Japan's Meteorological Agency, at least 100 millimeters of rain per hour poured overnight in some parts of Hokkaido.
He said at a news conference that unstable weather is anticipated to continue throughout Thursday due to low pressure systems.
"It is a situation where landslides, flooding, and serious calamities may occur at any time," Ebihara added, calling on residents in affected areas to follow the local authorities' instructions for safe evacuation.
More than 60 people were killed in western Japan last month after heavy rain and torrential downpours triggered landslides on August 20, which swallowed dozens of homes.
Landslides are common in Japan's populated mountainous areas, where there is frequent rainfall and many of the houses are built on or near steep slopes.
Last October, multiple mudslides killed 35 people, four of whose bodies were never recovered, in the volcanic island of Izu Oshima. The slides followed a typhoon that dumped a record 824 millimeters of rain in a single day.
Comment: The following video shows JR Shinkoiwa station in eastern Tokyo being flooded Wednesday eve due to heavy rain.
Is there is a method to the madness of the weather woes striking across the globe?
The Pacific Northwest is unmoving, static, while the rest of the Northern Hemisphere picks up the slack.
This is conservation of angular momentum being preserved.
Is it natural, artificially accentuated, or engineered?
If natural, it should be cyclic and confirmable in the past.
If artificially accentuated, it would require the least amount of work to achieve.
Totally engineered would be a monumental task.
The middle scenario would be insidious: If one is not paying attention on a regular basis to the state of Global Weather, one would be oblivious to the efforts taking place in plain sight.
What is your take on this subject?