According to the seasonal outlook from the US Forest Service, the developing La Niña will bring warm temps and an increased possibility of Santa Ana winds to SoCal in the next two months:
So far this summer, the lingering affects of the El Niño have kept much of the state under a cool, onshore flow regime as low pressure remained over the Pacific Northwest. This pattern will likely give way to more of an amplified pattern this fall with high pressure developing over the Southwest. This would lead to above normal temperatures for the September into early October timeframe. It is during that period when large fire potential may be highest for the season. Later this fall, cooler than normal weather may occur November into early December.
Here's their graphic version. (La Niña, which influences the course of the Pacific jetstream, tends to bring heat, wind, and dryness to SoCal, but cooler, wetter conditions to NorCal, above I-80.)
The Forest Service predicts four or five big fires in SoCal this fall. [h/p: OC Science]