Record Heat Meets a Major Snow Drought Across the West | Snowpack, a crucial water source for the region, was already scarce after a mild winter. Now, intense heat could make matters worse.

This heat wave is so extreme that it would only be expected to occur once about every 500 years in the current climate, according to World Weather Attribution, a group of scientists who study links between extreme weather events and climate change.

“These temperatures are completely off the scale for March, and our data shows that they would be virtually impossible in a world without human-caused climate change,” said Ben Clarke, a research associate in extreme weather and climate change at Imperial College London.

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