The Japan Meteorological Agency said Monday that extreme heat areas are expanding nationwide, with several locations in the Kanto region recording temperatures over 35°C [1].
This weather pattern increases the risk of heatstroke and infrastructure strain across Japan's most populous regions during the peak of summer. The simultaneous approach of tropical storms complicates emergency preparedness for local governments.
High temperatures have become widespread across the archipelago. In the Kanto region, more than 10 locations observed extreme heat days [2]. In some inland areas of Kanto, temperatures have exceeded 35°C [3]. This trend is not limited to the south; the agency said that midsummer days with temperatures above 30°C [1] have also occurred frequently in Hokkaido and Tohoku.
While the heat persists, tropical activity is intensifying in the south. A typhoon is currently approaching the Okinawa and Amami regions [4]. Some reports indicate the formation of Typhoon No. 11 on Monday, suggesting a "double typhoon" scenario where two systems are active simultaneously [5]. However, other weather reports have focused primarily on the movement of Typhoon No. 6 [4].
Local authorities continue to monitor the inland heat, as the expansion of extreme heat zones into the Kanto region marks a significant shift in the seasonal temperature gradient. The agency said that the heatwave has become evident on a national scale due to the persistence of high-pressure systems.
Residents in the south are advised to prepare for heavy rain and strong winds as the tropical systems move closer to land. Meanwhile, those in the Kanto and northern regions are urged to take precautions against extreme heat to avoid health complications.
“Hokkaido and Tohoku have also seen frequent midsummer days above 30°C.”
The convergence of a national heatwave and multiple tropical systems creates a dual-threat scenario for Japan. While the Kanto region manages urban heat island effects and record-breaking temperatures, the southern islands must prepare for storm surges and flooding. This puts significant pressure on the national disaster management system to allocate resources between heat-relief and storm-evacuation efforts.
