Japan Heat 2026
August 6 – August 25, 2026 Updated Aug 25
Every published chapter of The Fold's coverage of Japan Heat 2026, in one place — oldest to newest, updated as the story develops.
Japan’s worst heatstroke day on record: 4,105 people taken to hospital on 22 July
The Fire and Disaster Management Agency’s figures put 22 July above the previous daily high, set in 2018, by 296 people. The season read as light until late June; since then it has tracked the heaviest summer ever measured.
On Japan’s worst heatstroke day, 744 of the 4,105 ambulance calls came from a workplace
The rule Japan made mandatory in June 2025 does not require employers to prevent heatstroke. It requires them to notice it — and the ministry’s own casualty count hit a record while deaths fell 39%.
We reported 4,105 on Japan's worst heatstroke day. The final count is 4,134 — the fifth July running that the fire agency's first number came in low
Japan heatstroke correction: The Fold published 4,105 ambulance transports for 22 July. Japan's Fire and Disaster Management Agency finalised the month on Tuesday at 4,134, with twelve deaths rather than nine and 755 workplace calls rather than 744.