Three Japanese cities recorded temperatures of 40°C or higher on Tuesday, marking the first use of the term "kokushobi" — an extreme-heat designation introduced in April 2026 for days reaching that threshold.
Toyota in Aichi Prefecture hit 40.1°C, an all-time record for the city, while Tajimi in Gifu Prefecture reached 40.3°C and Gujo recorded 40.0°C, also a record high for Gujo. Nationwide, 731 of 914 observation points logged highs of at least 30°C by mid-afternoon.
The heat wave coincides with the Japan Meteorological Agency's three-month forecast released the same day, which projects average temperatures above normal for Okinawa and Amami, and at or above normal for the rest of the country through October. Precipitation is expected to remain near seasonal averages across all regions.