Japan and South Korea endure record-breaking summer heat fueled by climate change - August 2025

Japan and South Korea experienced extreme summer heat in 2025, with Japan recording its hottest June and July in 127 years. The Climate Shift Index (CSI) indicates that human-caused climate change made these events at least five times more likely, with several cities experiencing over a month of CSI level 5 temperatures.

• Japan experienced unprecedented heat in 2025, with June being the hottest on record by 2.3C (4.2F) above normal and July 2025 becoming the hottest in the countrys 127-year record, averaging 2.9C (5.2F) above the 1991-2020 average.
• South Korea recorded its second-hottest July since 1973 with an average temperature of 27.1C (80.7F), and Seoul set a new July record for the number of tropical nights, defined as overnight temperatures remaining above 25C (77F) between 6:01 p.m. and 9 a.m. the next day.
• Analysis using the Climate Shift Index (CSI) shows that from mid-June to early August, daily average temperatures in Japan and South Korea reached CSI level 5, meaning human-caused climate change made the event at least five times more likely.

APA

Climate Central (2025). Japan and South Korea endure record-breaking summer heat fueled by climate change - August 2025. https://www.climatecentral.org/climate-shift-index-alert/Japan-and-South-Korea-August-2025

Chicago

Climate Central. Japan and South Korea endure record-breaking summer heat fueled by climate change - August 2025. 2025. https://www.climatecentral.org/climate-shift-index-alert/Japan-and-South-Korea-August-2025.

Wikipedia

{{cite report |author=Climate Central |title=Japan and South Korea endure record-breaking summer heat fueled by climate change - August 2025 |date=14 August 2025 |url=https://www.climatecentral.org/climate-shift-index-alert/Japan-and-South-Korea-August-2025 |access-date=23 October 2026 |via=Climate Insights Directory}}

BibTeX

@techreport{climatecentral2025japan, author = {{Climate Central}}, title = {{Japan and South Korea endure record-breaking summer heat fueled by climate change - August 2025}}, institution = {Climate Central}, year = {2025}, month = aug, url = {https://www.climatecentral.org/climate-shift-index-alert/Japan-and-South-Korea-August-2025}, urldate = {2026-10-23}, note = {Indexed by Climate Insights Directory} }