"Climate change, including increased heat, extended drought, and a thirsty atmosphere, has been a key driver in increasing the risk and extent of wildfires in the western United States," the National Oceanic and Atmospheric Administration says.

The largest of the wildfires ravaging the area shifted direction, triggering more evacuation orders and posing a new challenge to exhausted firefighters.

Economic losses and damage are an estimated $135 billion and $150 billion, the costliest fire event in US history. Hurricane Helene in six states last fall caused up to $250 billion in damage.