Grim new death records as brutal heat plagues US south-west into the autumn

September has offered little reprieve after a sweltering summer, with Las Vegas on 102nd day of temperatures above 100F

Brutal heat continues to plague the south-west US, with excessive heat alerts lingering long into September as parts of the region set grim new records for deaths connected to the sweltering temperatures.

Autumn has offered little reprieve for cities that have already spent months mired in triple-digit temperatures. This week, Las Vegas, Nevada; Phoenix, Arizona; and Palm Springs, California, are all grappling with severe weather, with highs that have pushed over 100F (38C). More than 16 million people in the US were under heat alerts on Friday, according to the National Weather Service, mostly clustered in the southern tips of Nevada, Arizona and California.