File:Smoke across the Western United States (MODIS 2021-07-13).jpg

English: The combination of extreme heat and extreme drought have spurred a vicious start to the wildfire season in the Western United States—and have created an extreme smoke event. The last four days have seen all-time high temperature records reached or shattered in several Western states, while Death Valley hit 130˚F (54.4˚C). The warmest temperature ever recorded on Earth is 134˚F (56.7˚C), a record set in Death Valley in 1913. This is the third heatwave to brutalize the American West in 2021.

Although the drought in many parts of the West has been long-term, on July 7 the National Weather Service issued a Drought Information Statement noting record dryness of the past three months. This, along with areas of below normal snowpack and precipitation dating as far back as last winter have resulted in intensifying drought across portions of southeast Washington and continues across portions of central and north central Oregon. The U.S. Drought Monitor also shows that 85.4 percent of California is in “Extreme Drought” conditions, with 33.3 percent of that state also suffering the highest category, “Exceptional Drought”.

On July 11, 2021, the Moderate Resolution Imaging Spectroradiometer (MODIS) on board NASA’s Terra satellite acquired a true-color image of smoke shrouding much of the Western states. From the wildfires in southern Oregon, smoke stretches more than 900 miles (1450 km), stretching across the Rocky Mountains to reach eastern Wyoming and Colorado. The fire-created haze stretched from Saskatchewan, Canada to north-western Texas, a distance of about 2,000 miles (3,220 km). Many dozens of wildfires across Washington, Oregon, and California are the major contributors to this massive shroud of smoke.