Heavy rain warnings are in effect for the Hokuriku and Tohoku regions as the rainy season begins across northern Japan [1].
These weather patterns increase the risk of flash flooding and landslides in mountainous areas, while the simultaneous approach of a tropical cyclone threatens the southern islands.
Forecasters expect maximum 24-hour rainfall to reach 100 mm in Hokuriku and 120 mm in Tohoku [1]. The intense precipitation coincides with the start of the rainy season, which the Japan Meteorological Agency estimated began around June 20 and 21, 2026 [6].
While the north faces storms, conditions in Kanto and western Japan, including Tokyo, Osaka, and Nagoya, are expected to improve [1]. However, these regions will experience increased humidity and high temperatures. Tokyo is forecasted to reach a high of 27 °C, while Osaka may hit 28 °C [1].
In the south, officials are monitoring Typhoon 7 as it tracks toward the Ryukyu Islands [2]. Meteorological data suggests the storm could make a close approach to Okinawa in the latter half of the week, specifically around July 24-25, 2026 [2].
Residents in the affected northern regions are advised to remain vigilant against thunderstorms and sudden heavy downpours throughout the next 24 hours [1].
“Maximum 24-hour rainfall is forecast to reach 100 mm in Hokuriku and 120 mm in Tohoku.”
Japan is facing a complex meteorological window where the onset of the seasonal rains in the north converges with peak typhoon activity in the south. The simultaneous threat of high-volume rainfall in Tohoku and a tropical cyclone near Okinawa puts significant pressure on national emergency management and regional infrastructure during the early summer transition.
