Monday, Dec. 6, 2021 | 5:45 p.m.
Unseasonably warm weather cascaded over Las Vegas last week, when the city saw temperatures up to 16 degrees above normal rates.
John Adair, senior meteorologist at the National Weather Service in Las Vegas, said that because of the high atmospheric pressure caused by storms in the Pacific Northwest and British Columbia, the western United States has experienced a week of warm, dry and mild days. The stretch of warmer days began Nov. 27, when Las Vegans eyed weather forecasts consistently in the 70s. On Nov. 30, the city hit 77 degrees, 16 degrees above normal.
The normal temperature highs starting Nov. 1, Adair said, are approximately 60 degrees, with the low being 42. But this year, just before Thanksgiving, the temperature had held steadily from 61 to 62 degrees and continued to climb well into the 70s by the 27th.
On the first day of December, Las Vegas broke 75 degrees, just a degree above the previous high of 74 degrees in 1940. Monday, Adair said, marks the end of the pseudo heat wave.
"We're going to get in more of a winter-type pattern now," he said. "That ridge of high pressure is finally breaking and moving off to the east, and the storms are now going to start dipping into the western U.S. and southwest."
Although the city was well above its normal temperatures for the fall, winter is coming swiftly and promptly. Adair said residents can expect their first frost right on time, with cooler, lower-than-normal temperatures emerging Friday. He also said a "fairly weak" storm could breeze through Monday evening and Tuesday.
"We'll probably see freezing temperatures in parts of the valley Friday night into Saturday morning," he said. "The average occurrence for ... 32 degrees or below is Dec. 10, so we're about right on schedule."