Study Finds Dangerous Fire Weather Days Tripled Globally in 45 Years

More than half the increase attributed to human-caused climate change, researchers say.

Published on Feb. 22, 2026

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A new study shows the number of days with hot, dry, and windy weather that fuels extreme wildfires has nearly tripled worldwide in the past 45 years. Researchers found that over 60% of this global increase in synchronous fire weather days can be attributed to climate change from the burning of fossil fuels. The trend is even higher in the Americas, with the continental U.S. seeing an increase from an average of 7.7 such days per year in 1979-1988 to 38 days per year in the last decade. The southern half of South America saw an even more dramatic rise, from 5.5 days per year to 70.6 days per year, including 118 days in 2023.

Why it matters

This study highlights how climate change is increasing the likelihood of widespread, difficult-to-suppress wildfires around the world, as more regions experience the ideal weather conditions for fires at the same time. This puts a strain on firefighting resources, as countries may not have enough personnel and equipment to battle blazes popping up simultaneously across multiple regions.

The details

The researchers analyzed 45 years of weather data and found the number of days with hot, dry, and windy conditions that can fuel extreme wildfires has nearly tripled globally. They used computer simulations to determine that over 60% of this increase can be attributed to human-caused climate change from burning fossil fuels. The trend is especially pronounced in the Americas, with the continental U.S. seeing the number of such "synchronous fire weather" days rise from an average of 7.7 per year in 1979-1988 to 38 days per year in the last decade. In the southern half of South America, the average jumped from 5.5 days per year to 70.6 days per year, including a staggering 118 days in 2023.

  • From 1979 to 1988, the world averaged 22 synchronous fire weather days per year.
  • In 2023 and 2024, the world averaged more than 60 synchronous fire weather days per year.
  • In the continental U.S., the average number of synchronous fire weather days per year rose from 7.7 in 1979-1988 to 38 in the last decade.
  • In the southern half of South America, the average number of synchronous fire weather days per year rose from 5.5 in 1979-1988 to 70.6 in the last decade, including 118 days in 2023.

The players

John Abatzoglou

A fire scientist at the University of California, Merced and co-author of the study.

Cong Yin

A fire researcher at the University of California, Merced and lead author of the study.

Mike Flannigan

A fire scientist at Thompson Rivers University in Canada who was not part of the study.

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What they’re saying

“These sorts of changes that we have seen increase the likelihood in a lot of areas that there will be fires that are going to be very challenging to suppress.”

— John Abatzoglou, Fire scientist

“It increases the likelihood of widespread fire outbreaks, but the weather is one dimension.”

— Cong Yin, Fire researcher

“This study is important because extreme fire weather is the primary — but not only — factor in increasing fire impacts across the globe, and it's also important because regions that used to have fire seasons at different times and could share resources are now overlapping.”

— Mike Flannigan, Fire scientist

What’s next

Researchers plan to further study the impacts of climate change on wildfire risk and the ability of countries to respond to simultaneous fire outbreaks across multiple regions.

The takeaway

This study underscores how climate change is dramatically increasing the frequency of dangerous fire weather conditions worldwide, posing major challenges for firefighting and resource allocation as more regions experience peak fire risk at the same time.