Wildfire explodes in California wine country as heatwave scorches US west

Multiple fires have ignited this week with searing heat expected to last days and extend to Pacific north-west

Multiple wildfires have ignited across California as the state continues to scorch in a multi-day heatwave that is expected to last through the weekend.

The largest this week, named the Pickett fire, exploded in size on Thursday as it burned in a remote area of Napa county, and covered more than 3,200 acres (850 hectares) by Friday afternoon. Evacuation orders and warnings have been issued on Thursday for hundreds of residents around Calistoga, a small city in the region known for its wine, as firefighters faced challenging conditions, working through dangerously high temperatures and rugged terrain. The fire's perimeter is just 5% contained.