California asked residents to dial back their air conditioners this holiday weekend as the state tries to avoid a repeat of power shortages that weeks ago triggered the first rolling blackouts in 20 years. Electricity for delivery Friday in Southern California jumped by the most on record ahead of a heat wave that’s expected to tax the power grid. Sacramento is forecast to hit 110 degrees Fahrenheit (43 Celsius) on Sunday, according to the National Weather Service. Parts of Los Angeles could also reach 110.

The California Independent System Operator, which runs the grid, said Thursday it isn’t expecting blackouts. However, the ISO expects demand to be similar to the weekend of Aug. 14, when the earlier outages hit. It’s asking consumers to conserve energy in the afternoon and early evening from Saturday through Monday and has sent a notice to power generators across the state asking for extra electricity supplies.

“At this point, we aren’t forecasting any blackouts,” said Eric Schmitt, vice president of operations for the grid operator. “As we get closer and closer to each day, we will know better about the accuracy of our forecast.”