The temperature climbed to 42 C in Yangsan, about 310 kilometres southeast of Seoul, at 1:16 p.m. before rising further to 42.5 C at 1:26 p.m., according to the Korea Meteorological Administration (KMA), Yonhap News Agency reported.

Modern weather observations on the Korean Peninsula began in 1904.

It is the first time the country has recorded a temperature of 42.5 C.

Sunday also marked the fifth consecutive day that temperatures exceeded the 40-degree mark.

According to local media reports, meteorologists have warned that temperatures could climb even higher and potentially exceed 43 C in the coming days if the heatwave persists.

The previous highest temperature recorded in South Korea was 41.0 C, registered in Hongcheon, Gangwon Province, on August 1, 2018. Sunday's reading in Yangsan has now set a new national record.

In response to the extreme heat, the government activated a Level 2 emergency operation of its disaster response headquarters at 1 p.m. to strengthen the nationwide response, Yonhap reported.

It is the first time South Korea has activated the Level 2 emergency response for a heatwave.

Government data cited by Yonhap showed that 1,781 people suffered heat-related illnesses between May 15 and July 31, highlighting the growing impact of the prolonged spell of extreme temperatures.The number of patients who suffered from heat-related symptoms totalled 1,781 in the May 15-July 31 period, Yonhap reported quoting government data.

Away from South Korea, several European nations sizzled due to extreme temperatures this year.

This year marks the hottest June recorded for Western Europe and the second warmest globally, according to the latest report from a climate tracking service released on in July.

“Heatwaves like this are what we expect to see in a changing climate,” John Kennedy, head of climate information at World Meteorological Organization (WMO) had said.

The heat spikes are being driven by the highest sea surface temperatures on record for June, according to the monthly update from the continent’s Copernicus Climate Change Service.

Globally, the monthly average sea-surface temperature for the extra-polar ocean (60°S-60°N) was the highest for June, exceeding the previous record set in June 2024 by just 0.01ºC, partly reflecting the development of strong El Niño conditions in the equatorial Pacific, according to the service.

Death, drought and fires

The record-breaking heatwave has contributed to severe health impacts, including heat-related deaths.

Europe also saw widespread dryness that, together with extreme heat, contributed to wildfire activity and heightened drought risk in parts of eastern Europe.

The heat in parts of Western Europe is continuing in July, accompanied by localised violent storms and in some areas by worsening drought and the risk of wildfires, including in France and the Iberian Peninsula, according to WMO.

‘Silent killer’

Heat stress occurs when the body gains more heat than it can release, and extreme heat is often called the “silent killer”, remaining under-reported in many countries.

More than 200,000 heat-related deaths occurred in Europe over the past four years, according to the World Health Organization (WHO). Globally, WMO estimates there were approximately 489,000 heat-related deaths annually between 2000 and 2019.