Forecasts for more scorching heat and monsoon moisture brought calls for Californians to conserve electricity Wednesday, and warnings that lightning, thunderstorm winds and parched vegetation were a recipe for wildfires.

The heat wave was expected to be most extreme in the state's interior, chiefly the Central Valley where some locations hit 110 degrees on Tuesday, while the wildfire risk was focused on northern counties.

The California Independent System Operator, which manages the state's power grid, called for voluntary electricity conservation from 4 p.m. to 9 p.m., due to expectation of increased use of air conditioning and tightening power supplies.

CALIFORNIA 12-YEAR-OLD STEALS MINIVAN, LEADS DEPUTIES ON HIGH-SPEED CHASE

San Francisco news, Sacramento News

Officials in California warn residents to conserve electricity since a heat wave is on the way. (Fox News)

AMAZON VAN HITS, KILLS CALIFORNIA TODDLER: POLICE

Late afternoon through early evening is the period when the grid is most stressed due to high demand while solar energy production is decreasing.

Red flag warnings for fire danger were posted for the northern Coast Range, eastern Shasta County and the Mount Lassen area.

The National Weather Service warned of the possibility of "abundant lightning" and erratic gusts from thunderstorms.

CALIFORNIA MOM'S CIVIL RIGHTS LAWSUIT ALLEGES 'SOCIAL JUSTICE TEACHER' FORCED STUDENTS TO PICK COTTON

"Lightning can create new fire starts and may combine with strong outflow winds to cause a fire to rapidly grow in size and intensity," the weather service said.