For the sixth straight day, a Flex Alert will be in effect today seeking voluntary power conservation and increasing the hours users are asked to reduce strain on the state’s electrical grid while near triple-digit temperatures continue to drive up air conditioner use.

The California Independent System Operator—which manages the state’s power grid—issued the first Flex Alert of the week on Wednesday, urging residents to reduce electricity during peak hours, initially designated as 4 to 9 p.m. Additional Flex Alerts had been issued for the same hours each day since Wednesday.

Monday’s alert added an hour, extending the recommended conservation period to 10 p.m to reflect “projected market deficiencies.”

The alerts have worked thus far, with the state avoiding involuntary power cutoffs.

According to Cal-ISO, electrical demand on Thursday topped out at 47,357 megawatts, the highest figure since September 2017. The agency projected that demand could exceed that number on Sunday, Monday and Tuesday, with Tuesday’s forecast at 49,000 megawatts.

“The ISO is working with state agencies and market participants to bring all available energy resources online for what are expected to be the most challenging days of the heat wave,” according to Cal-ISO.

Cal-ISO has warned that more Flex Alerts are likely to be posted during the duration of the heat wave, which is expected to linger until at least Tuesday, possibly longer in some areas.

Long Beach on Sunday broke a heat record set in 1988, with temperatures rising to 108 degrees. The high on Monday was projected to be 94 degrees, with temperatures expected to remain elevated throughout the week, according to the National Weather Service.

The high on Tuesday is expected to be 88 degrees, 96 degrees on Wednesday, 89 degrees on Thursday, and 91 degrees on Friday. Temperatures over the coming weekend are expected to cool to the low-80s, with a chance of thunderstorms and rain.

Long Beach breaks heat record set in 1988