Summer is officially here, and for most quick serves that means more customers, later dinner rushes, and high school employees willing to work extra shifts. But for some chains, it means rolling out new, summer-themed menu offerings.

This month, Subway added avocado as a premium seasonal topping, available with a Turkey and Bacon Avocado sub; a Steak, Egg, Cheese, and Avocado breakfast sub; and a BLT with avocado.

Subway has been looking for a chance to use avocado for some time, says the company’s executive chef, Chris Martone. He says that while he’s long admired the fruit’s color and versatility, it wasn’t until this year that it became practical to roll out avocado nationwide.

“It seems like technology has finally caught up that we can have avocado without preservatives,” Martone says. “It’s been great. [In its] first week of sales in the restaurants, we set new all-time sales records for the company.”

Summer is peak avocado season—which makes sourcing easier for Subway’s 24,000 U.S. locations—but it’s also a time when customers are watching their waistlines, says Subway corporate dietician Lanette Kovachi. She says avocado is a good match for the health-conscious.

“It tastes great, but also it’s a nutritious product,” Kovachi says. “It’s rich in monounsaturated fats, it’s high in potassium and fiber. It’s a win-win.”

Cold Stone Creamery is another quick serve taking advantage of seasonal produce. The chain will launch a Strawberry Basil ice cream in July and a Mojito Sorbet in August.

Vice president of marketing Kate Unger says herb-infused ice cream was a natural next step for Cold Stone, which releases new special flavors each month.

“Our Tastemaster searches the Internet, he goes to different restaurants,” Unger says. “He has noticed that herbs have never been infused in ice cream flavors. For the summer, it’s a great way to cool off if you don’t want anything too heavy.”

“For the summer, herb-infused ice creams are a great way to cool off if you don't want anything too heavy.”

The Mojito Sorbet is a nondairy, nonalcoholic version of the popular cocktail. Unger says the refreshing mint taste should draw in people worn down by the heat of summer.

Other quick serves are looking to new proteins to spice up their summer offerings. Chipotle recently added chorizo, a type of sausage, in several New York restaurants and at least one Denver location as a test, says communications director Chris Arnold.

Domino’s, meanwhile, is hoping its chicken offerings, which were launched earlier this year, can encourage summer business, says spokesman Chris Brandon.

“I think a lot of people are still trying it and still realizing we have it,” Brandon says. “We definitely hope that through the summer, people will add chicken to their pizza orders.”

But while Domino’s chicken items are a permanent addition to the menu, many quick serves are using their summer items only as limited-time offers.

For example, White Castle is taking advantage of bacon’s popularity with LTOs including bacon and ranch sliders and bacon and ranch fries, available through July 2. Bruegger’s, meanwhile, is tapping in to the healthy summer vibe with a limited-time, low-calorie Skinny Zesty Egg White Sandwich, which includes a lower-calorie bagel and turkey sausage. And Cinnabon is fighting the heat with the Creamy ReTreat LTO, an ice cream drink with Oreo cookies and Ghirardelli chocolate sauce.

Subway’s avocado spread, initially launched as an LTO, might find itself on the permanent menu, says spokesman Les Winograd. He says that while franchisees aren’t required to keep the fruit around after the summer, they can continue offering avocado as long as they want.

“Right now all the restaurants in the U.S. have it for this advertising window through mid-July,” Winograd says. “About half the markets have elected to continue to promote it.”

While Cold Stone won’t add any of its summer flavors permanently, the company has found that the flavor-of-the-month idea is a strong promotional tool, Unger says.

“We’re looking at bringing it back next year,” she says. “Monthly may be too often, but next year we’ll probably do it three to four times a year.”

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