The average rate on a 30-year mortgage in the U.S. edged lower for the second week in a row, a modest but welcome boost for prospective home shoppers in the midst of the spring homebuying season.

The rate fell to 6.64% from 6.65% last week, mortgage buyer Freddie Mac said Thursday. A year ago, the rate averaged 6.82%.

The average rate has mostly trended lower since reaching just over 7% in mid-January. When mortgage rates decline, they boost homebuyers’ purchasing power.

Borrowing costs on 15-year fixed-rate mortgages, popular with homeowners refinancing their home loans, also fell this week, pulling the average rate down to 5.82% from 5.89% last week. A year ago, it averaged 6.06%, Freddie Mac said. — Associated Press