(ETH) – One of the most extreme heat waves ever observed in the western United States this early in the season is near its climax. The punishing blast of heat, which began Sunday, has set hundreds of records while simultaneously worsening a historically severe drought, intensifying fires, and degrading air quality.

About 40 million Americans have endured triple-digit heat and more than 50 million have been under excessive heat warnings this week. After focusing in the northern and central Rockies earlier in the week, the core of the heat has shifted into the Desert Southwest and California’s Central Valley, where scores of additional records are predicted to fall through Saturday.

California’s Independent System Operator, which manages the state’s flow of electricity, is encouraging residents to reduce their energy use Thursday evening. While it’s just mid-June and the hottest time of the year is historically still weeks away, temperatures have matched their highest ever observed levels in parts of Utah, Wyoming, and Montana.


Salt Lake City; Sheridan and Laramie, Wyo.; and Billings, Mont.; all made history Tuesday, soaring to 107, 107, 94, and 108 degrees, respectively. On Wednesday, the mercury in Las Vegas swelled to 116, just one degree shy of its highest temperature ever recorded.

Death Valley, Calif., famous for holding the world record for heat, hit 125 degrees, the highest temperature reached this year in the United States. Denver hit the century mark for a second straight day Wednesday, the earliest in the season it has reached 100 twice in a row. READ MORE

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