SAN FRANCISCO -- PG&E announced Saturday evening that it will be proactively shutting off power for safety in Butte and Yuba Counties due to high fire danger.
RELATED: PG&E restoring power to North Bay communities after day-long precautionary outage
PG&E says it will continue to evaluate weather conditions for a Public Safety Power Shutoff in Nevada, El Dorado and Placer counties.
Electricity was turned off around 6 a.m. to 1,600 customers in parts Napa, Solano and Yolo counties. Just as that shutdown was called off, the utility warned 27,000 customers in Butte, Yuba, Nevada, El Dorado and Placer counties that their power would be cut from 9 p.m. through Sunday morning.
Conditions ripe for fire - winds, low humidity, dry vegetation and heat - were expected to last into Sunday. The National Weather Service office reported a 71 mph (114 kph) gust on one peak in the region.
RELATED: Yolo County wildfire grows to 1,700 acres, 0 percent contained
A fire that erupted late in the day in Yolo County was estimated at 100 acres; firefighters halted the spread of another after 25 acres burned northeast of Calistoga in Napa County. The causes were not immediately known.
PG&E is under pressure to prevent fire starts after downed power lines and other company equipment have been blamed for conflagrations that began during so-called fire weather.
The shutoff in portions of the Sierra foothills began Saturday, June 8 at about 9 p.n. and impacts about 16,000 customers.
Here's a live outage map of areas affected.
ABC7 News contributed to this report.
PG&E to proactively shut off power in Butte, Yuba counties due to high fire danger