At a Glance
- An early July heat wave has gripped the West.
- While heat in early July isn't unusual, the magnitude and longevity has smashed some all-time records.
- Records have been set in California, Nevada and Oregon.
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A Western heat wave has already smashed all-time record highs and heat streaks, even by standards of the Desert Southwest and California.
This scorching heat kicked off around the July Fourth holiday weekend, and will only slowly relent in some areas this weekend.
(WEATHER MAPS: Temperature | Heat Index | 10-Day US Forecast)
Sin City Sweltered
Last Sunday, July 7, the official temperature sensor at Harry Reid International Airport in Las Vegas climbed to 120 degrees.
That crushed the city's all-time record of 117 degrees, set in 1942 and tied in 2005, 2013, 2017 and 2021.
But that wasn't the end of it.
Vegas soared to 119 degrees two days later on July 9, then 118 degrees on July 10 and 11. They sweated through their four hottest days in 87 years of records, and a record seven straight days with highs of 115 degrees or more.
Perhaps what's most stunning about this is the airport sits about 1,000 feet higher in elevation and 250 miles northwest of Phoenix, Arizona. Phoenix has only reached 120 degrees three times in 130 years, and hasn't done so since July 1995.
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Other All-Time Records
Among reporting stations with at least 70 years of records, 10 other locations, all in California, tied or set their all-time record highs during this heat wave. Most are plotted in the map below.
Palm Springs (124 degrees on July 5) topped its previous all-time standard from 2021, 1995 and 1993.
Barstow, in California's Mojave Desert north of Los Angeles, tied its all-time record (118 degrees) three days in a row from July 7-9.
Bishop, in California's Owens Valley at an elevation of just over 4,100 feet, chalked up five straight days with highs in the 110s in this heat wave. They had only two such days prior to this heat wave dating to 1943.
Finally, in northern L.A. County's Antelope Valley, both Lancaster and Palmdale soared to 115 degrees, tying the all-time record in Lancaster and topping the record in Palmdale.
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All-Time Heat Streaks
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This heat wave was also notable for how long it lasted. Here are the heat streaks that tied or smashed all-time records, in addition to the Las Vegas streak mentioned earlier:
- Most 95-degree plus highs in a row: 11 straight days in Sandberg, California topped a streak from late Aug. into early Sept. 2017
- Most 100-degree-plus highs in a row: 5 straight days in both Eugene and Salem, Oregon. (Each city averages only 1 or 2 such days an entire summer.)
- Most 105-degree-plus highs in a row: 4 straight days in Reno, Nevada (previous record was 2); 6 straight days in Winnemucca, Nevada (previous record was 4); and 4 straight days in Boise, Idaho (tied record from 2002)
- Most 110-degree-plus highs in a row: 6 straight days in both Lancaster and Palmdale, California. (That doubled the previous record streak of 3 straight days.)
Record Hottest First 10 Days Of July
Not surprisingly given this heat wave, it's been the hottest first 10 days of July on record for more than a dozen major reporting stations in the West from Washington state to Arizona, according to the Southeast Regional Climate Center.
Among those cities are Portland, Oregon; Sacramento, California; and Phoenix and Tucson, Arizona.
What About Death Valley?
The world record-holder for heat, California's Death Valley National Park, fell short of that all-time high.
But it was still searing.
For over a week straight, daytime highs topped out at 125 degrees or hotter, reaching 129 degrees on July 7. And their early-morning low temperature, if you want to call it that, dipped to 99 degrees on July 9.
Following that world record of 134 degrees in a July 1913 heat wave, Death Valley has only reached 130 degrees twice since, in July 2021 and August 2020.
As usual, that only attracted tourists wanting to experience extreme heat. Unfortunately, at least one death was attributed to the heat in the park, the Associated Press reported.
Why So Hot?
Intense heat is typical before the heart of the Southwest's rainy monsoon season shifts into high gear and expands.
In this case, though, a bubble of high pressure known as a heat dome set up camp for days over California and western Nevada, nosing north into the Pacific Northwest.
The strength and persistence of the heat dome and its sinking, dry air allowed temperatures to soar as far north as Washington state.
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Jonathan Erdman is a senior meteorologist at weather.com and has been covering national and international weather since 1996. His lifelong love of meteorology began with a close encounter with a tornado as a child in Wisconsin. He completed a Bachelor's degree in physics at the University of Wisconsin-Madison, then a Master's degree working with dual-polarization radar and lightning data at Colorado State University. Extreme and bizarre weather are his favorite topics. Reach out to him on X (formerly Twitter), Threads, Facebook and Bluesky.
