PORTLAND – One more day.

Forecasters say the heat wave that has baked Maine over the past couple of days, toppling records for high temperatures and electricity use, should begin to break tonight with the arrival of a cold front.

Instead of being in the mid- and upper 90s, highs should top out around 80 degrees Sunday, said Mike Kistner, a meteorologist with the National Weather Service in Gray. Temperatures will climb back to near 90 by the end of next week, but they won’t hit the levels seen this week, Kistner said.

On Friday, the temperature soared to 100 degrees in Portland for only the fourth time since records have been kept. The reading broke the Portland record for the date — 94 in 1994 — and topped the all-time high of 99 for any day in July.

The temperature briefly hit 101, but it didn’t last long enough to account for the official record, said Margaret Curtis, another weather service meteorologist. That was just short of the all-time Portland high of 103 degrees, set on Aug. 2, 1975.

At press time, Portland even set an all-time record for the highest low temperature — the coolest it was all day was 75 degrees early Friday.

There won’t be much relief today, with the high expected to go well past 90 for the third straight day, meeting the weather service’s definition of a true heat wave.

The official advice from Jim Budway, director of the Cumberland County Emergency Management Agency, is “go to the beach if you can.”

The heat led several communities, including Portland, Scarborough, Westbrook and Harrison, to open “cooling centers” Friday for residents who couldn’t follow Budway’s advice.

The centers are places for people to get a break from the high heat and humidity by staying in air-conditioned buildings. In some cases, that meant merely reminding residents that the buildings were open — Portland and Scarborough, for instance, used libraries as cooling centers, while Harrison opened town offices.

Portland’s centers — at the main library branch on Monument Square and in the Bernstein Room at the Barron Center — will reopen today.

Portland also kept its “splash pads” — run-through cooling fountains at city playgrounds on Stone Street, and at Payson Park, the Deering Oaks ravine and the Kiwanis Pool on Douglass Circle — open until 9 p.m. Friday and plans to do the same tonight.

It was so hot that Scarborough Downs canceled harness-racing for the day to ensure the health of the horses. A power line failure knocked several substations out of commission, leaving 13,000 Central Maine Power customers without electricity from Scarborough to Saco.

It couldn’t have come at a worse time for Funtown/Splashtown USA in Saco. The water and amusement park had to send several thousand guests packing on the hottest day of the summer.

Thankfully, no one was stuck on roller coasters or other rides.

“Horrible timing. Couldn’t be worse,” said Ed Hodgdon, sales and marketing director. He said guests were given vouchers to return on another day.

James Maxim didn’t expect the scorching heat as he and family members spent the week in Limington. By Friday, he’d had enough, fleeing the stuffy vacation home and hopping into the Saco River, where he found some relief even though the water was freakishly warm.

“There’s only so many cold beverages you can drink before you have to jump into something,” said Maxim, 33, of Lunenburg, Mass., who sat on smooth rocks as the water washed over him.

All those air conditioners and fans struggling to keep up with the heat pushed electricity use in the state to an all-time record of more than 1,700 megawatts, said John Carroll, a spokesman for CMP. The old record was 1,682 megawatts, set on July 19, 2005. Carroll said CMP will have a specific number for Friday’s usage in a couple of days.

The electricity number could have been higher if there were more air conditioners on hand. The Lowe’s store on Brighton Avenue was cleared out of units Thursday after starting the week with 100 air conditioners, said Bill Bouchard, the store manager.

Normally, Lowe’s stores can get more of a hot — pardon the expression — product from other stores, but they were cleaned out too, even in other parts of the country, Bouchard said.

“They’re hot, too,” he said.

Bouchard said the chain considers this to be the end of the season for air conditioners, so he’s not sure when he’ll get another shipment and how many units might come in.

Ted Trainer, the director of Healthy Aging for the Southern Maine Agency on Aging, said the elderly are particularly vulnerable to problems caused by the heat, and it’s important to check in with aging parents or neighbors to make sure they’re OK.

“The visit is what counts,” he said, because the elderly are often reluctant to call for help if they feel ill from the heat.

He said York County has set up a registry for the elderly who want to be checked on when there’s an emergency, such as a severe storm or heat wave. Town officials will either call or send police to check on people who have registered. He said those checks could be particularly valuable during the heat wave.

For everyone else, time is an ally, as more normal temperatures arrive tonight.

The Associated Press contributed to this report.

Staff Writer Edward D. Murphy can be contacted at 791-6465 or at:

[email protected]