“I always planned on having a serious relationship by this point,” said Hope, 28. “Then I was finally like, ‘Oh, if I don’t actually go out and look for it, it’s not going to happen.’”

A lot of other singles went looking, too. The lifting of health restrictions in many parts of the U.S. this summer—now likely a fleeting change—created a big moment for online dating.

Engagement on dating apps in the U.S. reached a record high in July. Daily active users on the most popular dating apps, including Match Group Inc.’s Tinder and Bumble Inc.’s women-driven app, topped 15 million users, according to research firm Apptopia, which began collecting data in 2015.

But renewed concerns about COVID-19, driven by the spread of the Delta variant, could pose another setback to people’s dating lives—and the businesses that profit from them. Investors will get a peek inside that dynamic when Match reports quarterly results after the close of trading Tuesday. Bumble reports next week.

Dating apps took a hit early on in the pandemic, when the virus was spreading rapidly and cities shuttered restaurants and bars, forcing people to stay home. “People were lonely, they were scared, they were isolated,” said Liesel Sharabi, an assistant professor at Arizona State University who studies communication in interpersonal relationships.

After a few months of isolation, people slowly made their way back to dating apps. Tinder and Bumble adapted by shifting part of their focus to helping people find friendships, not just lovers, and developing new video features and speed-dating games to keep users engaged. They also added an option for users to display their vaccination status on their profiles.

Emma-Claire Ziolkowski, a dietitian from Virginia Beach, Virginia, said she re-downloaded Tinder and another popular app, Hinge, this year after she was fully vaccinated and her home state lifted its major COVID-19 restrictions.

After more than a year spent largely in front of screens, an app seemed like the natural place to look for love, Ziolkowski said. “My favorite thing about dating apps as a whole is that you have access to people you would have never had access to.”