Marek Kučera 
Japan is enduring what experts are calling the most extreme and relentless heatwave in its recorded history, with over 400 temperature records already broken and more expected in the coming days. From Hokkaido to the southern islands, daily records of both maximum and minimum temperatures are falling in unprecedented numbers. Heat indexes have reached an astonishing 50°C, and forecasts suggest the worst may still be ahead.
📈Historic Heat Records Falling Daily
For several consecutive days, dozens of all-time June temperature records have been broken across the country:
- Miyagi Island: 32.6°C – new June record
- Tokushima, Anabuki, Takinomiya: 36.2°C
- Imabari: 35.8°C
- Nakamura: 35.1°C
- Akae: 34.9°C
- Tottori & Hagi: Above 37°C
- Ushiku: 37.1°C
- Shizuoka AP: 35.2°C
- Kisarazu: 35.0°C
- Onahama: 34.5°C
- Lake Kawaguchi: 34.0°C
- Odanosawa: 30.0°C
Every single day delivers new June records somewhere in Japan. Tokyo’s June temperature record is also under imminent threat as the heat spreads and intensifies.
🌃Unprecedented Warm Nights: Tropical Nights Even in the North
What makes this heatwave especially hazardous is the record-breaking warmth at night—offering no cooling relief and increasing the risk of heat-related illnesses.
- Stifling tropical nights recorded in northern Japan, including parts of Hokkaido where this phenomenon is almost unheard of.
- 27.5°C minimum at Tanegashima (Southern Islands)
- 16.5°C–16.6°C overnight minimums in Hokkaido towns like Rausu, Otsu, Tsuruoka, and Shiranuka
More than 300 records for June’s highest minimums have already fallen, including in Wakkanai, Suttsu, and across Nagano, Saga, Nagasaki, and Izuhara.
🌡️Endless and Expanding: “Eternal” Heatwave
Experts describe this as an “eternal heatwave”—a phrase now circulating in Japan’s media. Key points:
- 238 records in just 10 days, 68 more in the last 4 days alone
- Hundreds of additional records expected in the days ahead
- No end in sight, with record-setting temperatures forecast to continue well into July
JMA (Japan Meteorological Agency) confirms that this is one of the largest and most geographically widespread heat record events ever observed in the country.
⚠️Serious Health Risks & Climate Alarm
With heat indexes locally exceeding 50°C, the risk of heatstroke and dehydration is dangerously high. Elderly citizens, children, and outdoor workers are especially vulnerable. The persistence of high overnight temperatures is preventing the body from recovering—a major driver of heat-related fatalities during past Asian heatwaves.
Climate scientists view this event as a clear signal of shifting climate patterns in East Asia, where record hot summers have become more frequent in the past decade. This heatwave appears to break even those alarming new norms, indicating accelerating climate extremes.
🌏South Korea Also Hit
Neighboring South Korea is also experiencing historic June heat, including:
- 35.7°C in Geochang – new national June record
The broader East Asia region is now in the grip of a regional-scale extreme heat anomaly, and millions of people remain at risk as records continue to fall.
🧵In Summary:
- 400+ records broken in Japan and counting
- 50°C heat indexes recorded
- Tropical nights as far north as Hokkaido
- Dozens of cities breaking both high max and high min records daily
- Historic heat wave with no clear end in sight
- Extreme health risks and clear climate warning signs
Japan is currently enduring one of the most intense, widespread, and historically significant heatwaves ever documented—a climate event for the record books.
Illustration picture: https://www.triptojapan.com/blog/mount-fuji-best-time-to-visit-a-seasonal-guide
