April-to-June seasonally adjusted existing-home sales rose to 5.4 million units from 4.6 million in the year-ago quarter.
The 30-year mortgage rate has hovered around 7 percent this year and could fall lower this week as yields on 30-year Treasury bonds slid.
The nation's capital led home sales higher during the quarter with a 49 percent jump.
The Washington, D.C., metro area, including suburbs in Maryland and Virginia, is "one of the hottest areas in the nation," said National Association of Realtors economist Jason Altman.
Virginia existing-home sales rose 30 percent, while sales in Maryland rose 26 percent. South Dakota, where existing-home sales slid 13 percent in the quarter, came out at the bottom of the existing-home-sales list.
While third-quarter sales are likely to stay strong, Altman said, home sales could slow along with the economy in the fourth quarter.
Written By Tiare Rath