Heatwave hits southwestern USA: Arizona, California and Nevada on alert

Record temperatures were reached in the southwestern United States on Thursday, with some areas exceeding 43 degrees Celsius. The first heat wave of the year is expected to continue in the region for at least another day.

Although the official start of summer was still two weeks away, about half of Arizona, California and Nevada were under a heat warning that was extended until Friday evening, according to the National Weather Service.

At a campaign rally of likely Republican presidential candidate Donald Trump in Phoenix in the late afternoon, 11 people fell ill with heat exhaustion and were taken to the hospital, where they were treated and released, the fire department said.

The Phoenix weather service described the city as experiencing “dangerously hot weather.”

And in Las Vegas, Clark County Fire Rescue has responded to at least 12 calls for heat exposure since midnight Wednesday. Nine of those calls resulted in a patient being hospitalized. A county spokesman said the number is likely higher because heat can play a role in other calls, including calls for alcohol poisoning or reports of fainting, dizziness or nausea.

New record highs on Thursday included 45 °C (113 °F) in Phoenix, beating the previous record of 44 °C (111 °F) set in 2016, and 44 °C (111 °F) in Las Vegas, beating the 43 °C (110 °F) last reached in 2010. Other areas in Arizona, California and Nevada also beat the records by several degrees.

Even further north, at higher elevations, the heat has arrived weeks earlier than usual in areas that are normally 12 degrees cooler. That includes Reno, Nevada, where normal highs for this time of year of 80 degrees Fahrenheit rose to a record-breaking 99 degrees Fahrenheit on Thursday.

The National Weather Service in Reno predicted a slight cooling for this weekend, but only by a few degrees. In central and southern Arizona, this still means triple-digit highs, even up to 43 degrees Celsius.