A series of 29 wildfires ignited across Southern California in December 2017. Six of the fires became significant wildfires, and led to widespread evacuations and property losses. The wildfires burned over 307,900 acres (1,246 km²), and caused traffic disruptions, school closures, hazardous air conditions, and power outages; over 230,000 people were forced to evacuate. The largest of the wildfires was the Thomas Fire, which grew to 281,893 acres (1,140.78 km²), and became the largest wildfire in modern California history, until it was surpassed by the Ranch Fire in the Mendocino Complex, in the following year.