Editor's Note: This post was originally published on August 24, 2017 and has been updated with the most recent information.

A hot spell that began Sunday is keeping a firm, sweaty grip on Los Angeles. In a sign of just how hot it is, the Los Angeles Department of Water and Power said Thursday that its customers set a new all-time record for energy use.

“It’s extreme,” said spokesman Joe Ramallo. “At no point in our city history have customers used this much electricity during the hottest part of the day.”

The old record of 6,396 megawatts was set in 2014.

This heat wave was originally forecast to fizzle out by Labor Day weekend. But a new forecast released Thursday by the National Weather Service says above normal temperatures will continue for the next seven days, with “very hot conditions” through Saturday.

Temperatures will peak Friday and possibly shatter records, with highs in Downtown LA expected to top 100 degrees. An excessive heat warning is in effect through Saturday night.

Here are some of the forecasted highs for Friday:

Santa Monica airport : 95 degrees

: 95 degrees USC : 104 degrees

: 104 degrees Burbank airport : 107 degrees

: 107 degrees LAX: 90 degrees

The prolonged, sweltering heat is straining LA’s power grid.

“Because temperatures are so high for so many days, and it’s not cooling off at night you’re getting equipment at our local distribution centers that’s running at the highest levels. It’s like running a car for days on end without giving it a break.”

To help conserve energy, Ramallo says to set your thermostat at 80 degrees and refrain from using appliances that use a lot of energy, including dishwashers and washers and dryers.

Conservation reduces strain on local electric dist equipment and can help prevent outages. Please help conserve b/w 2-10pm. #SaveEnergyLA — LADWP (@LADWP) August 31, 2017

All of Los Angeles—including the beaches—is roasting.

When the heat wave started, a morning marine layer kept coastal areas cool in the mornings. But the fog has dissipated, meaning “some of that Valley heat” is reaching neighborhoods on and near the beach, the Weather Service said.

On Sunday, the onshore flow is forecast to return, cooling down the coast again.

Just how hot has it been in the Valley? On Tuesday, it was 104 degrees at Burbank airport, and Woodland Hills tied a high temperature record of 112 degrees set in 1996 and 1976.

Dangerous heat wave will continue thru Saturday. Triple digit heat for many areas, including inland coastal areas. #laheat #LAWeather #cawx pic.twitter.com/pkWYCXRr4Q — NWS Los Angeles (@NWSLosAngeles) August 31, 2017

It’s not just hot. Lightning strikes were seen were spotted Wednesday night across Southern California.

Is anyone else seeing lightening in Hollywood right now? Like in the hills toward the cross? #LAWeather #Summer #Hollywood #HollywoodBowl — Jackie O'Black (@jobrl) August 31, 2017

If you don’t have air conditioning at home, we’ve mapped 25 free places to cool off.