Overview

• The panel identified a northward‑displaced jet stream and a pronounced extension of the Tibetan high as the primary meteorological drivers.
• Japan’s June–August average temperature was 2.36°C above normal, the highest since nationwide records began in 1898.
• Hokkaido logged its hottest summer on record, with 21 of 22 major sites setting record seasonal averages and a regional anomaly of about +3.7°C.
• Experts said long‑term warming and unusually high mid‑latitude sea surface temperatures likely amplified the heat.
• Meteorological offices urged continued heat‑illness precautions as outlooks point to warmer‑than‑average conditions through September to November.