Amanda White, owner of Key Appliance in downtown Skowhegan, moves a portable air conditioner toward other AC units for purchase at the store’s appliance showroom on Thursday, as temperatures climbed into the 90s for a third straight day. Key Appliance had a variety of portable and window air conditioners available to those battling the heat. Rich Abrahamson/Morning Sentinel

For the third day in a row, temperatures in central Maine climbed into the mid-90s on Thursday — the first day of astronomical summer.

And if there’s one thing that has helped people withstand this week of scorching, unseasonable heat, it’s air conditioning.

At Dave’s Appliance in Winthrop, the heat drove shoppers to clear the shelves of air conditioners. By Thursday, the store had sold all of its 60 air conditioning units, with a delivery of 10 more expected Friday, according to Kim Caouette, logistics supervisor at the store on Central Street.

“That’s quite a few for us,” said Caouette. “It’s definitely crazy.”

In Augusta, temperatures appeared to be on track to break the daily record high of 95 degrees as of around 3:30 p.m., said Stephen Baron, a meteorologist with the National Weather Service’s regional office in Gray. A line of thunderstorms, potentially severe, and a cold front moving through northern New England Thursday afternoon into early Friday morning were expected to cool off temperatures after the record-breaking three-day stretch, according to the weather service.

In fact, the high temperature for the state capital topped out at 97 degrees Thursday, breaking the record that was set in 1953.

An excessive heat warning for much of the state was expected to end Thursday night at 8 p.m. Cooler temperatures and rain showers were expected throughout Maine into the weekend once the cold front moves through the area Friday, according to the weather service.

“We’ll see some relief tomorrow,” Baron said Thursday afternoon.

But when temperatures heat up again, many retailers, big and small, in central Maine still have plenty of air conditioners in stock.

Maeghan Hunnewell, manager of Key Appliance in Skowhegan, said the store at 101 Water St. stocked up ahead of the heat wave. Shoppers bought between 10 and 20 of them this week, Hunnewell said, and the store still had about 30 left in stock on Thursday. Prices ranged from about $200 to $600 per unit.

“We sell quite a bit during the summer,” she said.

Key Appliance in downtown Skowhegan had a variety of portable and window air conditioners for purchase for those battling the heat, as temperatures reached the upper 90s Thursday in central Maine. The store is located at 101 Water St. Rich Abrahamson/Morning Sentinel

At Ware-Butler Building Supply on North Street in Waterville, store manager Ethan Casavant said the store hasn’t sold any AC units this week — its shipment of six units was delivered Wednesday. Last year, the hardware store sold about 10 units, Casavant said.

“We should be selling some very quickly,” Casavant said Thursday.

Usually, shoppers head to Ware-Butler and other smaller retailers in search of an air conditioner only once the big-box stores sell out, Casavant said.

Cindy Batey, of Batey’s TV and Appliance in Fairfield, agreed. The store has sold some air conditioners this year and had about nine on hand Thursday morning.

“That’s where their mindset is,” said Batey of shoppers who prefer the big chains, adding that Batey’s offers services like installation that a large retailer like Walmart does not.

And even after three days of what forecasters called a “heat dome” sitting over the Northeast, it appeared the big-box stores were faring well — at least in Waterville.

As of Thursday morning, the air conditioner and fan aisle at the Waterville Walmart Supercenter was almost fully stocked, with dozens of units available. Across the parking lot at Home Depot, the display at the front of the store was somewhat picked over, with some models out of stock, but there were still several options to choose from.