The average rate on a 30-year U.S. mortgage edged lower this week, returning to its lowest level in about a year. The average long-term mortgage rate slipped to 6.3% from 6.34% last week, mortgage buyer Freddie Mac said Thursday. A year ago, the rate averaged 6.32%. The modest drop brings the average rate back to where it was two weeks ago, after a string of declines brought down home loan borrowing costs to their lowest since early October 2024. Borrowing costs on 15-year fixed-rate mortgages,