Extreme Heatwave Peaks in Western US, Breaking Records

An extreme early-summer heatwave was expected to peak across much of the western United States, with millions scrambling to cope as temperatures soared.

Las Vegas baked at 44°C, while Death Valley could top 49°C due to an oppressive high-pressure system smothering the region. The National Weather Service warned widespread temperature records were likely to be tied or broken in California, Nevada and Arizona.

Experts warn the unseasonable scorching heat could signal the start of a brutal summer. Dangerously hot temps in Las Vegas ran 10-15°F above average. Cooling stations opened and some events like a farmers' market moved indoors.

"One of the things with it being so hot so quickly is we really haven't had an opportunity to acclimate," said an ambulance official, noting that even locals' bodies aren't used to the abrupt heat.

California's Central Valley was "of particular concern" with little overnight relief forecast for those without effective cooling or hydration.

While temps should cool slightly in coming days, the heatwave is expected to expand into Oregon and Washington. But coastal areas like Los Angeles were spared the worst.

The punishing heatwave has swept in from Mexico, which recently saw its highest ever temperatures in Mexico City. Dozens have died and hundreds sickened by repeated heat waves scorching the country.

Experts warn this year is on course to be the warmest on record as human-caused climate change heats the planet at an alarming rate. The UN predicted an 80% chance Earth's temps will at least temporarily exceed the key 1.5°C mark in the next 5 years.

Last month was the hottest May ever recorded, pointing to climate change's growing toll through extreme weather, flooding, drought, melting glaciers and rising seas.