Average fixed mortgage rates fell for the third consecutive week as consumer confidence slipped and the federal government shut down, according to a weekly survey by Freddie Mac. The average 30-year fixed-rate mortgage is at its lowest level since late June.

According to Freddie’s Primary Mortgage Market Survey (PMMS), the 30-year fixed-rate mortgage averaged 4.22 percent for the week ending Oct. 3, down from last week when it averaged 4.32 percent. A year ago at this time, the 30-year fixed averaged 3.36 percent.

The 15-year fixed-rate mortgage averaged 3.29 percent this week, down from last week when it averaged 3.37 percent. A year ago at this time, the 15-year fixed averaged 2.69 percent.

Five-year adjustable-rate mortgages (ARMs) averaged 3.03 percent this week, down from last week when they averaged 3.07 percent. A year ago, the five-year ARM averaged 2.72 percent.

Frank Nothaft, vice president and chief economist for Freddie Mac, warned that the shutdown could have an ongoing depressive effect on consumer confidence, imperiling fourth quarter GDP while lowering rates.

"With the onset of the federal government shutdown and declining consumer confidence, fixed mortgage rates fell for the third consecutive week. Consumer sentiment fell for the second month in a row in September to its lowest reading since April, according to the University of Michigan. Moreover, a recent Bloomberg survey of professional forecasters suggests that a partial federal shutdown lasting one week would shave 0.1 percentage points off of GDP growth in the fourth quarter and even more if the shutdown lasts longer," he said in a statement.