Freddie Mac, a mortgage finance company, reported that the average 30-year fixed-rate mortgage was 6.66% on Aug. 27, up slightly from 6.65% a week earlier and above the 6.56% average a year ago, according to Freddie Mac.

The 15-year fixed-rate mortgage averaged 5.98%, compared with 5.95% a week earlier and 5.69% a year ago.