Last updated October 15, 2021
-

Western Wildfire Season 2020

Western US

Climate change was a key driver of the unprecedented fires that caused significant damage and devastation across the western US during the 2020 fire season. Rapid snowmelt in May, early season heat waves in late spring, the absence of the Southwest monsoon, anomalously warm seasonal temperatures, record heat waves in early fall, the hottest August through October period in western US history, and very high vapor pressure deficits had the effect of drawing moisture out of the fuels, priming the environment for explosive fire behavior.

In August, record heat, low humidity, and widespread dry lightning spawned nearly 1,000 fires in California. The situation escalated in September when seasonal offshore winds fanned the flames. Five of California’s six largest fires occurred in 2020, including the August Complex Fire, the largest fire in state history at 1.03-million acres. In early September, explosive fires in Oregon burned 900,000 acres in three days, almost double the amount that typically burns in an entire year. Washington state, which saw an average of 300,000 acres burn during the previous five years, saw 500,000 acres burn in just a few days. By mid-October, the Cameron Peak Fire in Colorado had grown to become the largest fire in state history. Colorado and California set new records for total acres burned in a single season. By December 31, 2020, the National Interagency Fire Center reported that US wildfires burned 10.27 million acres – the highest yearly total since accurate records began in 1983.

Get the details
western wildfire season
Greenhouse Gas Emissions
Global Warming
Land Surface Temperature Increase
Air Mass Temperature Increase
Large Scale Global Circulation Change
Snowpack Melting Earlier and/or Faster
Precipitation Falls as Rain Instead of Snow
Atmospheric Blocking Increase
Land Surface Drying Increase
Snowpack Decline
Southwestern US Precipitation Decrease
Extreme Heat and Heat Waves
Drought Risk Increase
Pine Beetle Outbreaks
Wildfire Risk Increase
Western Wildfire Season 2020