Temperatures could soar to 105 in the San Fernando, San Gabriel and Antelope valleys, and there's a chance of a few thundershowers in the San Gabriel and San Bernardino mountains this week as Southern California gets its first real taste of summer.
The National Weather Service said winds circulating clockwise around high pressure over the Rockies are pulling warm, moist air in from northern Mexico. High temperatures in the upper 90s and low 100s are expected in inland Los Angeles County and western San Bernardino County through Friday, with only slight cooling over the weekend.
"It's not that unusual for this time of year," said Dan Keeton, a weather service meteorologist. "It's summer."
Those circulating winds will reach the valleys, but they won't quite reach the coast, so temperatures at the beaches, downtown Los Angeles and much of Orange County should stay comfortably near normal, Keeton said.
Forecast highs in coastal communities in Los Angeles and Orange counties are mostly in the 70s and 80s this week, peaking in the upper 80s near Santa Ana and near 90 at the Los Angeles Civic Center.
Forecasters said there's a slight chance of afternoon and evening thundershowers in the mountains.