Freddie Mac says a 30-year fixed-rate mortgage fell to 3.66 percent this week, not much more than the all-time low of 3.31 percent in November 2012. A year ago, 30-year rates averaged 4.34 percent.

A 15-year fix now averages 2.93 percent, down from 2.98 percent last week. A one-year adjustable rate mortgage averaged 2.46 percent, up from 2.41 percent. Read More