A sudden weather front brought early-season rain and strong winds to the Japanese archipelago on May 21, 2026 [1].
The abrupt shift from unseasonal heat to the early stages of the rainy season, known as "tsuyu no hashiri," disrupted travel and increased safety risks for residents and tourists across the Kanto region.
Temperatures plummeted by approximately 10 °C compared to the previous day [1]. The weather system impacted several areas, including Odaiba in Tokyo, parts of Hyōgo prefecture, and the Hakone area in Kanagawa [1, 2]. Local authorities warned of heightened landslide risks due to the intensity of the rainfall [2, 3].
In Hakone, the severe weather forced the suspension of the popular pirate-ship tours on Lake Ashinoko [1, 3]. The cancellation affected various international visitors, though some maintained a positive outlook despite the conditions.
"I am used to rain in the UK. So I will enjoy it as much as possible," a British tourist said [1].
A Canadian tourist expressed disappointment over the boat cancellations but noted the scenery remained attractive. "I thought I could take the sightseeing boat. We will go back to Hakone-Yumoto. But it is still beautiful here," the tourist said [1].
Similarly, an Indian tourist mentioned the inability to see Mount Fuji due to the clouds. "I am enjoying it very much. I want to see Mount Fuji, but probably it is impossible. Still, it was fine. I will drink some warm coffee," the tourist said [1].
While the primary report dates the event to May 21, 2026 [1], some secondary reports listed the date as April 21, 2026 [4].
“Temperatures plummeted by approximately 10 °C compared to the previous day”
The arrival of the early rainy season and the accompanying sharp temperature drop highlight the volatility of Japan's spring-to-summer transition. For the tourism sector, these abrupt shifts create operational challenges for outdoor attractions and require visitors to be prepared for extreme weather variability, while the increased landslide risk underscores the perennial geological vulnerability of the Kanto region during heavy precipitation.
