WASHINGTON (AP) — Average U.S. rates on fixed mortgages rose this week for a second straight week but remained near historic lows.

Mortgage buyer Freddie Mac says the average rate for a 30-year loan increased to 4.20 percent from 4.14 percent last week. The average for the 15-year mortgage jumped to 3.31 percent from 3.23 percent.

Rising prices and higher interest rates beginning in mid-2013 have made homes less affordable for would-be buyers. At the same time, a limited supply of homes is available to buy. Mortgage rates are about a quarter of a percentage point higher than they were at the same time last year.

Mortgage rates tend to follow the yield on the 10-year Treasury note. The 10-year note traded at 2.64 percent Wednesday, up from 2.60 percent a week earlier.