The managers of California’s power grid are calling for voluntary electricity conservation between 4 p.m. and 9 p.m. Wednesday because of soaring temperatures and tightening power supplies.

These hours are when the grid will be stressed due to high demand and the nightly fall-off in solar production.

Reducing energy during a Flex Alert can stabilize the grid and prevent power outages.

Highs of 104-105 Degrees Through Saturday

There is a National Weather Service Excessive Heat Watch in effect until 11 p.m. Wednesday when it becomes a Heat Advisory.

The expected highs today through Saturday will be about 104 or 105 degrees in the San Joaquin Valley, the weather service says. A slight cool-off to 100 and 99 will follow Sunday through Tuesday.

There will be afternoon thunderstorms in the Sierra through the weekend.

Cooling Centers

In Fresno, the city opens cooling centers from 1 p.m. to 7 p.m. whenever the weather service predicts a high of 105 or hotter.

FAX buses provide free service to and from the cooling centers along regularly scheduled routes when the centers are open. Leashed pets are allowed at the cooling centers.

The cooling centers are:

• Frank H Ball Community Center, 760 Mayor Ave.
• Mosqueda Community Center, 4670 E Butler Ave.
• Pinedale Community Center, 7170 N San Pablo Ave.
• Ted C Wills Community Center, 770 N San Pablo Ave.

Cooling Center Activities

While visiting the city’s cooling centers, residents can enjoy board games, play basketball at the gymnasiums, read a book, or participate in activities led by recreation staff.

Recreation staff lead camps, workshops, senior fitness, ceramics, arts, movie screenings, and water fun days. Daily activities at all community centers are posted to PARCS social media accounts.