Blistering June heat, unprecedented April snow: Climate change makes extreme weather more likely in Oregon

Portland shattered its highest-ever temperature in June, cresting at 116 degrees. On Monday, the record for latest snowfall also fell after a rare shot of winter weather left the city blanketed in heavy, wet snow.

As heat-trapping gases continue to accumulate in the atmosphere — coming from tailpipes, power plants and industrial facilities — these types of extreme weather events are likely to become more common, said Erica Fleishman, a professor at Oregon State University and director of the Oregon Climate Change Research Institute.

“As the climate changes, all types of weather extremes will be more likely,” she said. “Heat waves become more likely, and yes, even though global temperatures are rising, cold spells become more likely, too.”

Fleishman points out that, of course, there have been weather extremes for as long as there has been weather, and records have been broken as long as they’ve been kept.

Records are being broken in different ways of late, however. An analysis by The Associated Press found that between 1999 and 2019 the number of record-high temperatures broken in the U.S. was about twice that of record-low temperatures.

In a stable climate, the numbers would be close to equal.

That trend in Oregon is evident in events like the heat dome event of late June, which likely would never have occurred at that intensity without the warming effects of climate change, according to scientists who specialize in identifying links between extreme weather events and climate change.

While the heat dome, which killed nearly 100 people in Oregon, was a 1-in-1,000 year event, it could be more like a 1-in-10 year event by the end of the century if more isn’t done to curb greenhouse gas emissions, Fleishman said.


“As the climate changes, all types of weather extremes will be more likely."