South Korea has recorded its highest temperature since modern observations began, with the mercury reaching 41.4 C in the southeastern city of Yangsan.

It comes as a prolonged heatwave has pushed temperatures above 40C for a third consecutive day across parts of the country.

According to the Korea Meteorological Administration (KMA), the record was set at 1:40 p.m. (04:40 GMT) on Friday.

The reading exceeded the previous national record of 41.0 C, which was set in the city of Hongcheon back in August 2018.

The KMA has issued its highest-level heatwave warning for parts of South Gyeongsang Province, including Yangsan, while heatwave advisories and warnings remain in effect across most of South Korea.

"KMA data records using the ASOS observing system began in 1973, and the 41.4 degrees measured in Yangsan is the highest temperature observed in our records since then," a KMA spokesperson said.

The KMA said the extreme heat across the country was caused by the simultaneous influence of the North Pacific High and the Tibetan High pressure systems, which have covered the Korean Peninsula like a lid, trapping heat and allowing temperatures to build across much of the country while limiting cloud cover.

Forecasters are also monitoring Typhoon Dolphin in the western Pacific, whose eventual track could influence weather conditions over the Korean Peninsula next week, although its impact on the ongoing heatwave remains uncertain.

The record in South Korea comes as ongoing wildfires have forced hundreds of thousands to evacuate in Spain and France.

Scientists said on Friday that human-caused climate change made the extreme weather fuelling blazes in southwestern France twice as likely, and made the conditions driving fires in central Spain 20 times more likely.

The World Weather Attribution group of scientists used historical weather observations to assess how "fire-prone" hot, dry and windy conditions, which indicate how difficult it is to suppress a fire once it starts, have changed over time.

Greenhouse gas emissions, mostly from burning coal, oil and gas, have increased the planet's average temperature to around 1.4 Celsius above pre-industrial times, according to the World Meteorological Organization.

In today's climate, extreme fires of this intensity are likely to occur once every 20 years in southwestern France, and once every six years in central Spain, the analysis said.

“We’ve seen repeatedly how climate change increases hot, dry, flammable conditions that are extremely conducive to wildfires," said Clair Barnes, a research associate in extreme weather at Imperial College London, who co-authored the WWA analysis.

"What’s unique about this case is that it’s still early in the season — and with another heatwave looming, these findings are extremely scary," Barnes added.