Key Facts
• August 30, 2025: Kanto and Tokai regions experience rapid morning temperature rise.
• Tokyo reached 35°C by 10:20 AM, marking its 24th extreme heat day this year.
• Gunma’s Kiryu City recorded 38.5°C, the highest nationwide by 11:30 AM.
• Afternoon forecasts predict 40°C in Nagoya and Kofu, 39°C in Kumagaya, and 38°C in Tokyo.
• Eastern Japan and Western Japan classified as “extremely dangerous” heat zones.
• Heat compression phenomenon caused by high-pressure systems contributes to rising temperatures.
• Heatstroke risk is significantly elevated; strict precautions are advised.
• Recommendations include avoiding outdoor activities during peak heat, staying hydrated, and using air conditioning indoors.
Summary
On August 30, 2025, the Kanto and Tokai regions of Japan experienced dangerously high temperatures, with Tokyo reaching 35°C by mid-morning and forecasts predicting up to 40°C in some areas by the afternoon. This marks Tokyo’s 24th extreme heat day of the year. The heat is driven by a high-pressure system causing a heat compression effect. Cities like Nagoya, Kofu, and Kumagaya are expected to face temperatures exceeding body heat, posing severe heatstroke risks. Authorities urge residents to avoid outdoor activities during peak heat, stay hydrated, and use air conditioning to mitigate risks. Eastern and Western Japan are under “extremely dangerous” heat warnings.
