The rainy season began Tuesday in Honshu and Shikoku following its start in Kyushu on Monday, the Meteorological Agency said.
The announcement means the rainy season has started on all the main islands of the archipelago except Hokkaido, which normally does not experience it.
The agency declared that the season began in Kyushu on Monday, and in the Okinawa region and Kagoshima Prefecture's Amami area on May 10.
The start of the season in the Tohoku region comes a day earlier than last year. But it began one to seven days later in other parts of Honshu, including the Kanto and Chugoku regions, and in Shikoku.
Rain and overcast skies are expected to be widespread across Japan except Hokkaido and will likely last about a week due to a typhoon currently moving northward and a low-pressure system developing over the south.
