The Kanto region is forecast to experience its highest temperatures of the year today, May 29, 2026 [1].
This sudden surge in heat during late May increases the risk of heat-stroke and puts pressure on public health systems before the traditional summer peak.
Warm air aloft and strong sunlight are expected to drive these unusually high temperatures [1, 2]. In Kofu, the maximum temperature is predicted to reach 33°C [1], while central Tokyo is expected to hit 31°C [1]. This marks the second "manatsubi" — or midsummer day — for Tokyo this year [1].
Weather officials are monitoring Utsunomiya and Nerima, where the number of midsummer days in May could reach a record-high count [1]. The extreme heat is not limited to today; two additional days with temperatures above 35°C are expected on May 31 and June 1 [1].
The Japan Meteorological Agency said the likelihood of significant high temperatures, the kind that typically occur only once per 10 years, has been increasing since early May [7].
Due to the intensity of the heat, the agency issued warnings to the public. "As a measure against heatstroke, please hydrate frequently," the agency said [1].
Residents in the Kanto-Koshin area and the Tokai region are advised to remain vigilant as the heatwave persists through the start of June [1, 2].
“The Kanto region is forecast to experience its highest temperatures of the year today.”
The occurrence of midsummer temperatures as early as May suggests an anomalous weather pattern for the Kanto region. When temperatures that typically appear once per decade surface in the spring, it indicates a shift in seasonal norms that may lead to higher energy demands for cooling and increased medical emergencies related to heat exhaustion earlier than the government's standard summer preparedness window.
