The National Weather Service said this will likely be one of the most intense heat waves seen in many years across desert Southwest, including parts of California, Arizona, Nevada, and Utah. Large cities such as Phoenix and Tucson in Arizona, Las Vegas in Nevada and Sacramento in California have already issued warnings on the heat wave that could last up to 10 days. PHOENIX (AP) — The Latest on an extreme heat wave in the Southwest U.S. (all times local):

American Airlines says seven regional flights have been delayed and 43 have been canceled because of a heat wave threatening to bring 120 degrees to Phoenix. The National Weather Service forecasts a high of 120 degrees (49 degrees Celsius), which is has only hit three times in recorded history — the last time 22 years ago. Temperatures in the high desert are about 15 degrees above average, Fisher said, with the heat wave expected to cool a few degrees each day starting Wednesday. #azheat pic.twitter.com/REMwhT2FQP — NWS Phoenix (@NWSPhoenix) June 20, 2017

-- On Sunday, several Northern California cities -- including Sacramento (106 degrees), San Jose (103 degrees) and San Francisco (88 degrees) -- saw record hot temperatures. “Don’t sit in your house because they are worried people will be complacent inside, close their drapes then it gets really (hot) and then bad things happen.”

According to Aljazeera, the overnight temperatures won’t drop like normal, leading to heat-related illnesses.
A heat wave strikes the Western U.S. states of Arizona, California, and Nevada. It is predicted to last until June 23.