An estimated 24.6 million travelers will take to the skies on U.S. airlines over the Thanksgiving holiday travel period, according to an airline trade group.

Airlines for America said the number of travelers over the period running from Nov. 21 to Dec. 2 is forecast to be up 1.5 percent from the estimate for the same period last year.

The busiest day will be Sunday Nov. 30 with 2.6 million travelers, which is also expected to be the busiest travel day of the year. The second-busiest day of the Thanksgiving period will be Monday Dec. 1, and the third-busiest will be Wednesday Nov. 26.

The least busy days will be Thanksgiving and the day after Thanksgiving.