More Americans signed contracts to buy homes in February, with purchases surging in the Midwest ahead of the traditional spring buying season.

The National Association of Realtors says its seasonally adjusted pending home sales index rose 3.5 percent to 109.1, rebounding from a 3 percent decline in January. The index has reached its highest level since July 2015.

The increase in signed contracts occurred last month despite a shortage of homes on the market.

Regionally, signed contracts climbed 11.4 percent in the Midwest, with more modest gains in the South and West. In the Northeast, the number of contracts dipped 0.2 percent.

Pending sales contracts are a barometer of future purchases. A sale is typically completed a month or two after a contract is signed.