Japan, South Korea Record Hottest Summers in History
Japan and South Korea have endured their hottest summers on record, with both countries setting new benchmarks for average seasonal temperatures, underscoring the growing impact of climate change across East Asia.
The Japan Meteorological Agency (JMA) announced that average temperatures between June and August were 2.36°C higher than normal, making it the hottest summer since records began in 1898. This marks the third consecutive year Japan has broken summer heat records. The extreme conditions also triggered a public health crisis, with more than 84,500 people hospitalized for heat-related illnesses from May through late August, slightly up from last year’s figures.
South Korea’s Meteorological Administration likewise confirmed a record-breaking season. The country’s national average temperature this summer hit 25.7°C, surpassing the previous high of 25.6°C recorded in 2024. Adding to the severity, July registered 22 “tropical nights”—when temperatures remain above 25°C overnight—breaking a 117-year-old record previously set in 1994.
The relentless heat has had consequences beyond health. In Japan, rising sea temperatures have devastated marine ecosystems, slashing sea urchin harvests and driving prices to unprecedented levels.
On Rishiri Island in Hokkaido, a once-common sea urchin rice bowl now costs as much as ¥15,000 to ¥18,000 ($100–$120), double its price only a few years ago.
Officials in both Tokyo and Seoul have warned that such extreme summers are no longer anomalies but part of a troubling trend. Meteorologists point to the combined effects of global warming and shifting ocean currents, which have amplified the intensity of heatwaves across the region.
The record-breaking summer has intensified calls for stronger climate adaptation strategies, ranging from expanded cooling shelters and healthcare preparedness to energy policies aimed at reducing dependence on fossil fuels. For many in Japan and South Korea, the season of 2025 will be remembered not only for its record heat but also as a stark reminder of the mounting human and economic costs of a warming planet.
