The 30-year fixed-rate mortgage sunk to a 3.89 percent average this week, its lowest level since May 30, 2013. That translates to more mortgage savings for home buyers and refinancers.

Averages mortgage rates for the week ending Dec. 4:

30-year fixed-rate mortgages: averaged 3.89 percent, with an average 0.5 point, dropping from last week's 3.97 percent average. Last year at this time, 30-year rates averaged 4.46 percent.

15-year fixed-rate mortgages: averaged 3.10 percent, with an average 0.5 point, dropping from last week's 3.17 percent average. A year ago, 15-year rates averaged 3.47 percent.

5-year hybrid adjustable-rate mortgages: averaged 2.94 percent, with an average 0.5 point, dropping from last week's 3.01 percent average. Last year at this time, 5-year ARMs averaged 2.99 percent.

1-year ARMs: averaged 2.41 percent, with an average 0.4 point, dropping from last week's 2.44 percent average. A year ago, 1-year ARMs averaged 2.59 percent.