LOS ANGELES (AP) — A potentially record-setting heat wave is headed for the Western United States.
A strengthening ridge of high pressure lifting out of Mexico is on course to scorch portions of Arizona and southeast California this weekend.
Temperatures are expected to reach 118 degrees in Phoenix on Sunday, 119 degrees Monday. The National Weather Service says such heat is "rare, dangerous and deadly."
Phoenix is accustomed to triple digits but the upcoming extreme heat is rare.
Scientists say heat spells will become more common as the planet warms from man-made greenhouse gas pollution.
Health experts advise people to watch for heat-related illnesses.
A swath of the West Coast sweltered under heat warnings earlier this month.
The hottest day on record in Phoenix occurred June 26, 1990; it was 122 degrees.