Historical records continue to be rewritten as extreme heat in the West threatens 40 million Americans on Thursday.
An unseasonably hot air mass has spurred highs to rise into the 90s and triple digits across much of the West this entire week, already smashing records in Wyoming, Utah, Arizona and Southern California.
Death Valley, already the holder of the hottest record on Earth with a reading of 134 degrees in 1913, established a new daily record of 125 Wednesday.
On Tuesday and Wednesday, Denver had rare back-to-back 100 degree days, which has only happened 14 times on record. And this week was the earliest in the year it has done that. It could even have a rarer trifecta of triple digits, with Thursday's forecast high flirting right around 100 degrees. The last time it had three 100-degree days in a row was 2012.
The National Weather Service in Flagstaff noted it was likely that nearly every square inch of Arizona set a record high Wednesday.
Las Vegas soared to 116 degrees Wednesday breaking a record of 114 degrees for the date, and was only 1 degree shy of the record high of 117 degrees.
Finally, it hasn't just been a day or two of record-setting heat but a relentless streak. When Tucson soared above 110 degrees Wednesday that made it the fifth day in a row the city endured that blistering heat. The record of consecutive days of 110 degrees or hotter is six set in June 1994. A forecast for three more days of 110 degrees or more will beat that.
And Tucson is not alone in having to endure the high heat for several more days. The entire Western region will continue to bake under temperatures 10 to 30 degrees above average through the weekend.
The scorching highs are also infiltrating eastward, breaking records in Colorado, Nebraska, Kansas and more. Records will likely topple again in Las Vegas and Phoenix, where highs are expected to surge above 110 in the coming days. Denver and Grand Junction, Colorado, will likely break their previous records for Thursday of 98 and 100, respectively, by several degrees. The heat will also threaten record highs in Kansas City, St. Louis, Tulsa, Oklahoma, and Omaha, Nebraska.
And research reveals the fingerprints of climate change are all over these increasingly hot temperatures and longer heat waves. Compared to 1970, Phoenix now experiences eight more days a year of 110 degrees or higher and Denver 14 more days a year of 95 degrees or higher.
With the brutal heat continuing through the weekend, California power grid operators have issued a flex alert, or a plea for voluntary energy conservation, in an effort to reduce the risk for outages.
California Gov. Gavin Newsom on Thursday signed an emergency proclamation aimed at freeing up additional energy capacity, his office said. It suspends some permitting requirements and allows the use of back-up power generation. The proclamation says that "conditions of extreme peril" exist.
Multiple brush fires have sparked in the San Joaquin Hills near San Jose, California, and over 100 firefighters have been dispatched to contain them. Extremely low humidity and gusty winds will enable flames to rapidly spread across parched vegetation.
About 4 million people were under red flag warnings Thursday.
Climate experts are also concerned that these flammable conditions appearing so early in the fire season are a sign that 2021 will be another record-setting wildfire season in California, possibly spawning fires that could incinerate millions of acres by year's end.
But for the short term, there's relief in sight. The high heat finally breaks early next week as temperatures return to near average or even below average for some spots.