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The huge wildfires across California in recent weeks have underlined what fire experts describe as the new normal for the state. But firefighters say it’s more than just the scale and the timing of the fires that is different.

Chris Anthony, a division chief at the California Department of Forestry and Fire Protection, says fire behavior appears to be changing on a more micro level. One example: In mountainous terrain, fires typically run much faster uphill as the fire heats the fuels above it, making them more readily combustible.

But Mr. Anthony says his firefighters are seeing more examples of fires running fast downhill, too.

Another example: Firefighters for decades were accustomed to seeing fires slow down considerably at night, said Scott L. Stephens, a professor of fire science at the University of California, Berkeley. But a number of recent fires have continued to advance rapidly through the night.

“Many times now in the evening fires are burning at night almost as active as they are in the day,” Professor Stephens said. “Things are happening here in California that 10 years ago I never heard about.”