Arizona has warmed faster than any other state since 1970, with temperatures rising at a rate of 0.72 degree Fahrenheit per decade.
Climate expert Gregg Garfin of the University of Arizona points to a decade from 2001 to 2010 when his state was the hottest on record in both spring and summer.
He says warmer winters have caused that season’s precipitation to fall as rain rather than snow, allowing streams and the soil to dry out more quickly when spring’s arid heat arrives.
This is leaving more dry vegetation to burst into flames when struck by lighting or ignited by other factors.
A policy of putting out all fires that was established about 1900 has also disrupted the natural rhythm of the landscape, leaving vast amounts of flammable material piled up and ready to catch fire under the hotter and warmer conditions of the 21st century.