The average U.S. 30-year fixed-rate mortgage rate dropped to 3.91 percent, matching an all-time low, in the week ended Dec. 5, according to home mortgage guarantor Freddie Mac.

The 30-year rate was down from 3.95 percent in the previous week and far below the rate at the same time last year, when it averaged 4.77 percent. Rates have been below 4 percent for five consecutive weeks, reflecting historic levels of home affordability. Due to tighter underwriting standards, many homeowners find themselves unable to get approval for mortgages, which has dampened sales.

But recent reports have suggested a turnaround in the market.

Fixed mortgage rates started the year a little lower this week just as recent data reports indicate the housing market and manufacturing industry are showing signs of improvement, said Frank Nothaft, vice president and chief economist of Freddie Mac, in a statement.

Pending existing home sales in November jumped 7.3 percent, nearly five times greater than the market consensus forecast, to its strongest pace since April 2010. In addition, construction spending rose 1.2 percent in November, supported by the residential sector which exhibited its fourth consecutive monthly increase. Similarly, manufacturing expanded in December at the fastest pace in six months, he said.

Average 15-year fixed-rate mortgages averaged 3.23 percent in the week ending Dec. 5, down from 3.24 percent in the previous week and 4.13 percent in the previous year.

Five-year Treasury-indexed adjustable rate mortgages (ARMs) averaged 2.86 percent, down from 2.88 percent in the previous week, and 3.75 percent in the previous year.

One-year Treasury-indexed ARMs averaged 2.80 percent, up from 2.78 percent in the previous week and 3.24 percent in the previous year.