Wildfires across Japan and South Korea fueled by climate change

Unseasonably high temperatures have swept across South Korea and Japan, contributing to dangerous wildfire conditions from March 21, 2025, to March 26, 2025. Human-caused climate change has significantly amplified the likelihood of this heat, further intensifying fire risks in areas already grappling with severe drought.

Note: This event may continue beyond March 26th. Use the Global Climate Shift Index map to stay updated on heat in your region.

How unusual is the forecasted heat?

• During the wildfires, temperatures in South Korea climbed 4.5°C to 10°C (8.1°F to 18°F) above the 1991-2020 average, while western Japan exceeded the average by as much as 7°C to 8.5°C (12.6°F to 15.3°F). Human-caused climate change strongly influenced these temperatures.

• The peak of this unusual warmth is expected to continue on Wednesday, March 26th, with high temperatures forecast to exceed 22°C to 25°C (72°F to 77°F) in affected regions of South Korea and Japan.

• Unusually warm temperatures combined with low humidity dry out vegetation, increasing the wildfire risk by allowing fires to ignite and burn faster. 

How has climate change influenced this heat?

• From March 21 to March 25, daily maximum temperatures reached Climate Shift Index (CSI) levels of 5 in several of South Korea’s southern provinces and cities, including Jeollanam-do, Gyeongsangnam-do, Busan, Ulsan, and Daegu. 

  • A CSI level 5 indicates that human-caused climate change made this heat at least 5 times more likely, signifying an exceptional climate change event. 

• CSI levels of at least 2 impacted most of Japan during this time. Some isolated regions of CSI 4 or 5 will be possible in some of Japan’s southern prefectures on March 26, including Miyazaki, Kagoshima, Kochi, Ehime, and Yamaguchi, along with locations farther north in southern Hokkaido.

• CSI levels of 5 are expected to continue impacting South Korea’s southern provinces until March 26, while CSI levels of 2 to 3 are forecast to impact Japan until March 27. 

What other factors contributed to these fire conditions? 

• Severe drought conditions continue to persist following drier-than-average conditions that emerged late in 2024, driven by dry continental winds from the north and a lack of winter snowfall. 

• Officials attribute the high fire risk in part to dry vegetation, particularly an abundance of leaves on forest floors.  

• In South Korea, westerly spring winds grow hotter and drier as they cross the Taebaek and Sobaek mountain ranges. This allows for rapid wildfire growth amid low humidity.

• The region has been caught between two weather systems — low pressure to the north and a high-pressure system to the south — amplifying stronger winds and the overall wildfire potential.

What do experts say?

Kaitlyn Trudeau, a senior research associate at Climate Central, said: 
“With many areas facing severe drought, the added strain of climate change has made extreme heat events like this far more likely, turning dry landscapes into dangerous fire fuel."

To request an interview with a Climate Central scientist, please contact Abbie Veitch at aveitch@climatecentral.org. 

How do we know climate change is influencing this heat?

The Climate Shift Index uses peer-reviewed methodology and real-time data to estimate how climate change has increased the likelihood of a particular daily temperature.

We compare the likelihood that these temperatures would occur in a world without carbon emissions released by humans, versus in today’s world with decades of carbon emissions building up in the atmosphere. This is an established scientific method to determine how much climate change has or has not affected individual extreme weather events.