After a particularly wet rainy season fueled growth of lush vegetation, the sweltering summer of 2017 dried those plants to a crackly, combustible crunch. Several locales had racked up record temperatures, including a historic thermometer high of 106 in San Francisco on Sept. 1. Wildfires were an inevitable consequence, but none so fierce as October’s infernos that consumed vast swaths of the state’s iconic Wine Country.