Extreme Heat Sets Records, Stage For Fires In West

Extreme heat continues to bake the American West, breaking temperature records, and exacerbating drought and other wildfire catalysts. Billings, Mont. broke a 61-year-old record with 106°F heat on Monday, Boise, Idaho has hit 95°F for 23 days straight, and Salt Lake City hit 100°F for the 17th time this year on Sunday, just four shy of its annual record. The extreme heat, dangerous in its own right, combined with the megadrought across the region, augurs danger for extreme wildfires in the  near future. Nearly all of Idaho, and large portions of Montana, Wyoming, Oregon, and Washington are under red flag warnings, denoting the potential for “extreme” fire behavior.

Monsoonal moisture moving north from the Southwest could set off “dry thunderstorms” that cannot produce enough moisture to overcome the dry heat and result in rainfall, but still cause lightning strikes that can ignite wildfires. The drought and high temperatures also combine to increase fire risks for years to come — pine beetles proliferate rapidly in those conditions, potentially killing millions of trees and providing kindling for future fires. (Washington Post $, New York Times $, AP; Climate Signals background: Extreme heat and heatwaves, Drought, 2021 Western wildfire season)