Temperatures along the San Diego County coastline will approach 90 degrees on Thursday and Friday and inch toward 100 across inland valleys and foothills, the National Weather Service said.
The region will remain unusually warm through Tuesday, and there won’t be any rain to cool things off.
“A ridge of high pressure is going to hang over us longer than we expected,” said Lauren Villafane, a weather service forecaster.
A heat advisory will be in place for all areas west of the mountains from 10 a.m. Thursday to 8 p.m. Friday.
Early forecast models suggest that a second ridge could develop next week around Wednesday and last two to three days.
“In fact, there is some indication that temperatures next week could be even higher than what is forecast for this week,” the weather service said in a statement.