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.
The Forest Service predicts four or five big fires in SoCal this fall. [h/p: OC Science]