An unseasonably intense heat dome has settled over the American Southwest, pushing temperatures past 100 degrees Fahrenheit in Phoenix, Las Vegas, and Tucson on Tuesday. Phoenix recorded a high of 107 degrees, shattering the previous April 14 record of 101 set in 1989 and marking the earliest date the city has ever reached 107.
The National Weather Service has issued excessive heat warnings across southern Arizona and southern Nevada through Thursday, cautioning that overnight lows will only drop to the mid-70s, providing little relief. Health officials are urging vulnerable populations, particularly the elderly and those without air conditioning, to seek cooling centers.
Meteorologists say the early heat wave is consistent with a long-term trend of hotter and earlier extreme heat events across the Southwest. Water managers are also watching closely, as the premature heat is accelerating snowpack melt in the Rocky Mountains, potentially reducing the water supply available later in the summer.
