Heat warnings are in effect across region as record-high temperatures are forecast in California, Nevada and Arizona

Millions of people in the western US are preparing for extreme heat as unprecedented temperatures are forecast across California, Nevada and Arizona.

The National Weather Service (NWS) issued a heat advisory for California’s Bay Area and central coast regions as temperatures are expected to reach up to 90F (32C).

“Dozens of daily high temperature records are expected, and many locations are likely to set both all-high temperatures for the month of March and their earliest 100 [degree] temperature on record,” said the NWS Weather prediction center in a statement.

This is the first time in history that such a warning has been issued in March for the region, as temperatures are upwards of 20F to 30F above average.