Anticipating strong holiday travel, United Airlines said on Thursday that it will offer 3,500 daily flights within the United States in December, the most in any month since the pandemic began.

United said it plans to offer 91 percent as many domestic flights in December as it did in the same month in 2019, though the company’s final schedule could still change. That month, United will debut new direct routes — and restart a handful of others.

The airline plans to place an emphasis on flights connecting the Midwest to warm-weather destinations like Las Vegas and Orlando or ferrying travelers to ski slopes. Flight searches for holiday travel are up 16 percent compared with the same time in 2019, the airline said.

“We’re seeing a lot of pent-up demand in our data and are offering a December schedule that centers on the two things people want most for the holidays: warm sunshine and fresh snow,” said Ankit Gupta, vice president of network planning and scheduling at United.

United and other airlines enjoyed strong demand this summer because of widespread vaccinations, though the spread of the Delta variant of the coronavirus slowed that momentum going into the fall. The industry had hoped that corporate travel would restart in a big way after Labor Day, but many professionals have not returned to offices full time and business travel remains down.

Overall, air travel appears to have settled at about 75 percent of 2019 levels in September, according to data from the Transportation Security Administration. The Biden administration’s plan to relax travel restrictions on vaccinated foreigners starting next month is expected to provide another boost, especially around the holidays.

United said it expects the Wednesday before Thanksgiving and the Sunday after the holiday to be particularly busy. It also expects Thursday, Dec. 23, and Sunday, Jan. 2, to be popular travel days.