A heat advisory for the area is in effect until 9 p.m. Saturday. Temperatures in Calistoga are expected to reach a low of around 59 degrees Friday night and a high of near 91 degrees on Saturday, with 5 to 7 mph winds. The chances of dry lightning are low but “not zero,” the weather service said in its forecast discussion.

A fire burning near Silverado Trail wineries prompted evacuation orders in Napa County. The Pickett Fire was reported around 3 p.m. on Thursday, Aug. 21, off Pickett Road, near Calistoga. By Friday afternoon, it had burned 3,235 acres (5 square miles) with 5% containment, the California Department of Forestry and Fire Protection said.