Late last June, farmers in Walla Walla, Washington, noticed something odd happening to their onions. Walla Walla, an oasis in the middle of the state’s high desert, is bursting with vineyards, wheat fields and acres of the city’s eponymous sweet onions. As temperatures climbed above 100 degrees Fahrenheit, then above 110 degrees, the oversized onions began to burn, pale blisters forming underneath their papery skins. When the temperature reached 116, the onions started cooking, their flesh dissolving into mush.
Four miles away is the Washington State Penitentiary. It’s one of the country’s oldest prisons, established in the 1880s, before Washington achieved statehood. In June 2021, over 2,000 people were incarcerated in its large concrete buildings. In the Hole — the name incarcerated people use for the solitary confinement unit — the air conditioning had stopped working. Dozens of people spent 23 hours a day locked in small concrete and metal cells, even as temperatures continued to soar.
Washington isn’t known for extreme heat, but far above the fields and prison, two air pressure systems had collided, creating a massive heat dome: a cap of warm air that sealed in the heat and blocked the flow of cool marine breezes from the Pacific. The resulting weeklong heat wave brought some of the hottest temperatures that the state has ever experienced.
In a particularly alarming trend, climate change is causing average nighttime temperatures to warm even faster than average daytime temperatures, said Deepti Singh, a climate scientist at Washington State University who studies extreme weather events. This is especially dangerous because it limits the body’s ability to cool down, significantly increasing the risk of heat-related illnesses.
Researchers predict that if global temperatures continue to rise, similar events could happen as often as every five to 10 years before the end of this century in the Pacific Northwest. According to Singh, the Washington State University climate scientist, future heat waves could be even longer, hotter and more widespread.