Topline:
As the sea breeze weakens and high pressure builds over the area, a heat wave is going to bake Southern California this week. Temperatures are expected to hit summer levels between Wednesday and Friday.
The forecast: Upper 80s along the coast, 90s in the valleys and mid-90s in the deserts. That's about 15 degrees above average for this time of year.
This weekend: Temperatures should drop back to around normal by Sunday.
And it's dry: Drought conditions have continued to spread across the region due to a poor showing of rain this year (about 50% of normal). Heat waves will dry out vegetation faster than it normally would, potentially leading to an earlier start to fire season.