Jun 14, 2023 - Energy & Environment

Dangerous fire weather conditions becoming more common across U.S.

Change in fire weather days, 1973 to 2022
Data: Climate Central; Map: Kavya Beheraj/Axios

Fire weather days — featuring a volatile mix of low humidity, strong winds and high temperatures — have increased in number across much of the Lower 48 states during the past 50 years, a new analysis shows.

The big picture: An analysis from Climate Central, a nonprofit climate science research organization, found that wildfire seasons are getting longer and more intense, especially in the West.

  • Many parts of the East have also seen increases in fire weather days, the report finds.

Why it matters: The trend in fire weather days demonstrates how climate change is altering risk levels at the local and regional levels, with much of the phenomenon tied to human-caused climate change, per Climate Central.

Zoom in: The report uses weather data from 476 recording sites across the country during the years 1973-2022.

  • It finds that Southern California, Texas and New Mexico have experienced some of the greatest increases in fire weather days each year, with some areas now seeing around two more months of fire weather compared with a half century ago.

Yes, but: The Climate Central analysis has not been peer reviewed, though the data and method it relies on are widely used in the scientific literature. It also matches findings from peer-reviewed research.

  • For example, a study published this week in the journal Proceedings of the National Academy of Sciences found that "nearly all" of the increase in burned area across California during the past half-century is tied to human-caused climate change.

Between the lines: The Climate Central data shows that some places, including parts of Texas, California, Oregon and Washington, are experiencing fire weather conditions more than twice as often now than in the early 1970s.

  • Western interior regions saw greater increases in fire weather compared with Western coastal regions, where higher humidity levels mean dry air thresholds are reached infrequently.
  • However, fire weather thresholds were still reached in some coastal areas of the West, indicating there is risk there too.
  • In the East, the report finds parts of North Carolina are now seeing two more weeks of fire weather compared with the 1970s, and parts of New York and northern New Jersey have had an increase of about 10 days since 1973.

The intrigue: Not every region is seeing an increase in fire weather days.

  • Parts of Idaho, North Dakota and South Dakota have experienced a decline in the frequency of fire weather days.
  • Per Climate Central, the Dakotas have been cooling slightly, which can be tied to agricultural development.

The bottom line: Climate change is ratcheting up wildfire risks across much of the country. With more people than ever living in areas prone to fires, managing such risks is going to be more of a challenge.

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