Severe lightning strikes and a guerrilla thunderstorm hit Tokyo and several other Japanese prefectures on May 13, 2026 [1].
These sudden weather shifts pose significant risks to urban infrastructure and public safety, as the intensity of the storms coincided with peak commuting hours in the capital.
The storm struck the Roppongi area of Tokyo and extended to Inagawa town in Hyogo Prefecture, with similar reports coming from Kyoto and Fukushima [1, 2]. Residents in these areas witnessed intense lightning and a sudden downpour. In Hyogo, the storm brought large hailstones that covered streets and vehicles [1, 2].
Reiko Sato of Aqua Farm said the amount of hail was significant and that she had seen such a sight for the first time in her life [1]. Another resident who recorded the event said the rain and hail started suddenly and was unlike anything they had experienced [1].
The weather shifted rapidly following three consecutive summer days in Tokyo [1]. During the guerrilla thunderstorm, temperatures plummeted from approximately 35 °C to the 24 °C range [3].
Meteorologists attribute the volatility to unstable atmospheric conditions, which were likely influenced by recent heavy rain [1]. While some reports described this as the first guerrilla thunderstorm of the season in Tokyo, other records indicate a similar event occurred in the Itabashi ward on May 8 [1, 2].
Weather officials expect the unstable conditions to continue through May 14, 2026 [1].
“I have seen such a sight for the first time in my life.”
The rapid temperature drop and the occurrence of hail in May suggest an unusually volatile spring-to-summer transition. These 'guerrilla' storms are characterized by their sudden onset and localized intensity, making them difficult to predict and dangerous for commuters and agricultural operations in regions like Hyogo.
