Summer has arrived, and with it a brutal heat wave that has scorched the western United States. The temperature was expected to soar to 119 in Phoenix on Tuesday, a June 20 record for the city. Temps might climb to 127 in the aptly-named Death Valley.

The severe heat has canceled flights out of Phoenix and has been blamed for buckling roads, raging fires, and power outages in California, the nation’s most populous state.

Excessive heat warnings have been issued for inland California, southern Nevada, and parts of southwest Arizona through Friday. More than 29 million residents in California are under a heat warning or advisory.

Click here to see America’s hottest cities.
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Heat kills more people in the United States, over a 30-year average, than any other natural hazard, according to the National Weather Service. Last year, excessive heat was blamed for 94 fatalities, second only to the 126 deaths attributed to flooding.

The National Oceanic Atmospheric Administration reported Monday that the average global temperature in May 2017 was 1.49 degrees above the 20th-century May average of 58.6 degrees. This May was the third-hottest on record since the organization began collecting data in 1880.

The year-to-date average global temperature through may was 1.66 degrees above the 20th-century average of 55.5 degrees. This is the second-warmest for this period, behind the record set in 2016.

24/7 Wall St. reviewed data from the National Oceanic Atmospheric Administration on U.S. cities that report the most days a year with exceptionally high temperatures.