UNITED STATES: Much of the Western United States continues to remain affected by the scorching heatwaves with temperatures exceeding 104°F. Furnace Creek, in California’s Death Valley, recorded a maximum temperature of 127.7°F on June 17, which is a new world record for the month and only 34.16°F off the all-time global temperature record, 129.92°F.
With temperatures way above 100°F for days on end marked yet another climate extreme for residents of the region already suffering through a devastating drought and with memories of last year’s horrific wildfire season still imprinted on people’s minds. Spanning across a six-day period during the middle of June 2021, a dome of hot air languished over the western U.S., causing temperatures to skyrocket.
The heat extended much farther than the Southwest. Salt Lake City, Utah, saw its all-time record when temperatures hit 107°F on June 15, the last day of a three-day streak of high temperatures over 100°F. From June 13-19, high temperatures averaged 100°F. Billings, Montana, also reached its all-time high of 108°F.
The Full Picture
This extreme heatwave occurred over parts of the country stuck in a deep drought. Over 20% of the country is in the worst two categories of drought (D3-4: Extreme and Exceptional). The vast majority of the land located in areas also recently saw record-setting temperatures.
Drought and heat are natural dance partners. Drought conditions become extreme when temperatures soar, and vice-versa, hot temperatures turn even hotter by a drought-stricken landscape. When the ground absorbs incoming sunlight, some of that energy converts soil moisture into water vapor, which carries heat away from the surface. Less moisture in the soil means less solar energy being used to evaporate water. Instead, that energy heats both the ground and the air.
Naturally, one consequence of hot temperatures and a dry region is a heightened risk for wildfires. And during the middle of June, that risk turned to reality as wildfires sprung up in California, Arizona, Colorado, Utah and Montana. While the North American summer monsoon is normally expected to tame down wildfire risk across the Southwest, the wildfire season is just beginning for the rest of the West.
It’s always difficult to immediately quantify how much impact climate change has had on a climate extreme, but there is plenty of evidence to show that high temperatures and heatwaves have become worse due to climate change.
According to the Climate Science Special Report, which made up the scientific basis for the fourth National Climate Assessment, not only have temperatures risen in the past but they are projected to continue to increase due to the release of greenhouse gases.
In particular, as noted in the aforesaid report, extreme temperatures are expected to increase even more than average temperatures across the contiguous U.S. Events like this heatwave might be rare now, but they are expected to become more common by the end of the century.