But some residents of Mabi had shrugged off the warnings, however, given the area's history of floods.
A man stands next to a flooded residential area in Kurashiki, Okayama prefecture.
Japan is being battered by rainfall three times more than is usual for the month of July. Most of the deaths were in Hiroshima and the surrounding area.
In Okayama prefecture, rescue workers flew in helicopters over areas that are still under flood water and otherwise unreachable, looking for signs of life.
Japanese broadcaster was claiming that more than 160 people had been killed in the floods.
Dozens of people are still missing, and with the rains finally letting up on Monday, rescue workers were able to reach previously cut-off places where authorities fear more bodies may be trapped beneath debris.
"I can't go back if I wanted to", the 66-year-old retired Self-Defense serviceman said, holding a bird cage in which the birds chirped.
Officials have evacuated about two million people after rives banks burst. "I hope they find him soon".
Chief Cabinet Secretary Yoshihide Suga told a news conference Monday that 68 people were unaccounted for, many of them in the hardest-hit Hiroshima area.
The rains are the deadliest weather disaster in Japan since two typhoons that hit back-to-back in August and September 2011, killing almost 100 people.
Japan's government set up an emergency management centre at the prime minister's office and some 54‚000 rescuers from the military‚ police and fire departments were dispatched across a wide swath of south-western and western Japan. Water and other relief supplies were scarce in some areas. Residents lined up for water under a scorching sun as temperatures rose to 35 Celsius (95 Fahrenheit), raising the risk of heat stroke.
According to the Ministry of Health, Labor and Welfare, as of 1 pm on July 8, about 267,000 households in 11 prefectures, including Hiroshima, were without fresh water supply.
According to the West Nippon Expressway Company, at least seven expressway sections including those in Hiroshima and Okayama prefectures remain severely damaged with little chance of fix anytime soon.
Prime Minister Shinzo Abe warned at an emergency government meeting that "the situation is extremely serious" and ordered his government to "make an all-out effort" to rescue those affected.
Abe, who cancelled a foreign trip this week as the disaster worsened, was due to visit the flood-ravaged Okayama area to see the scale of the damage first-hand. Officials in Ehime prefecture asked the central government to review a weather warning system, noting that rain warnings were issued after damage and casualties were occurring.