U.S. mortgage rates entered August close to their highest levels in a year, extending the affordability squeeze for homebuyers. Freddie Mac’s latest weekly survey put the average 30-year fixed mortgage at 6.66%, up from 6.58% a week earlier, while the 15-year fixed rate rose to 6.04% from 5.96%. Mortgage News Daily’s index showed the average 30-year fixed rate at 6.83%, only 2 basis points below its 52-week high. U.S. 30-Year Mortgage Rate History. Mortgage rates do not move directly with the federal funds rate; expectations for inflation, Treasury supply and long-term bond yields usually matter more.