The National Weather Service defines “extremely critical” fire weather as winds of >30 mph and relative humidity of less than 10% in the presence of drought conditions and temperatures warmer than 70 degrees.

This is the first time it's ever happened in January.

https://www.fastcompany.com/91256483/the-horrifying-l-a-wildfires-are-being-fueled-by-the-worst-conditions-january-has-ever-seen