An analysis of record rainfall events across Japan from August to September 2026 found that global warming may have increased precipitation by around 20%.
The cases included the heavy rain in Chiba in August 2026 and rainfall associated with Typhoon No. 25. Researchers said warming may have affected each event examined.
The study was conducted jointly under the Ministry of Education, Culture, Sports, Science and Technology’s Advanced Research Program for Climate Change Prediction and by the Japan Meteorological Agency’s Meteorological Research Institute.
