The timing of "fire season" in California is variable, depending on the amount of prior winter and spring precipitation, the frequency and severity of weather such as heat waves and wind events, and moisture content in vegetation.
Northern California typically sees wildfire activity between late spring and early fall, peaking in the summer with hotter and drier conditions. Occasional cold frontal passages can bring wind and lightning. The timing of fire season in Southern California is similar, peaking between late spring and fall. The severity and duration of peak activity in either part of the state is modulated in part by weather events: downslope/offshore wind events can lead to critical fire weather, while onshore flow and Pacific weather systems can bring conditions that hamper wildfire growth. ==Nationwide fire season==