South Korea recorded its hottest temperature in 122 years on Sunday, August 3, 2026. The southern city of Yangsan hit 42.5°C (about 108.5°F), according to the BBC. No temperature this high has been measured in the country since it started keeping modern records over a century ago.

At least 19 people have died during the heatwave, authorities said as of August 5 (BBC). The number had been 16 just a day earlier, per Reuters, and it is still rising. At least 13 of the 19 victims were 80 years old or older. Older adults are more vulnerable to extreme heat because their bodies are less able to cool themselves, and they are more likely to have other health problems (Reuters).

On Tuesday, August 4, President Lee Jae Myung declared the heatwave a national disaster and called on authorities to step up their response (AOL; Reuters). A national disaster declaration is a formal way of saying the situation is too big for local governments to handle on their own. It unlocks emergency money and puts national agencies in charge of coordinating help, so resources can reach the worst-hit areas without waiting for the usual budget approvals.

Seoul, the capital, is under a severe heat warning for the first time under a new alert system the government created this year specifically to deal with rising temperatures (BBC). Think of it like a storm warning, but for heat. The fact that it went off in Seoul for the first time at the same moment the country set an all-time record means the system is being tested at its absolute limit right out of the gate.

The 42.5°C reading in Yangsan is not a close call. It is the highest temperature ever recorded across the entire Korean Peninsula, going back 122 years (Reuters; The Independent). The previous record had stood for years. Weather experts at the Korea Meteorological Administration will now study exactly how and why this reading was so high.

The large number of elderly victims raises questions about whether enough is being done to protect older people. Measures like regular check-ins by neighbors or community workers and accessible air-conditioned cooling centers in neighborhoods with many older residents may need to be expanded.

What sets this heatwave apart from earlier ones in South Korea is that three major things are happening at once. First, a real 122-year record was broken, not just a hot summer day. Second, the new heat-warning system designed for exactly this kind of crisis was triggered in Seoul for the first time. Third, the death toll is still going up, rising from 16 to 19 in just one day.

In the coming days, the death toll may climb further, because heat-related deaths can sometimes occur days after the worst exposure. The new alert system will also be closely watched to see whether its warnings and response plans are strong enough for the level of heat the country now faces. And if the Yangsan record is confirmed after standard weather checks, it will become the new benchmark against which all future heatwaves in South Korea are measured.