IMF head Christine Lagarde warned of souring global growth prospects at a Council of the Americas speech Wednesday. But this hasn't registered in the U.S. housing market yet, according to Freddie Mac's latest Primary Mortgage Market Survey.

Thirty-year fixed-rate mortgages averaged 3.85% during the week ending Oct. 1 — merely a one-basis-point decrease from last week, the weekly report found. The 15-year FRM averaged 3.07%, also a one-basis-point increase from the week ending Sept. 24.

Similar short-term trends were observable in adjustable-rate products. The five-year Treasury-indexed hybrid loan and one-year Treasury-indexed ARM were both unchanged week-over-week, averaging 2.91% and 2.53%, respectively.

But given a longer outlook, these indicators have dropped significantly. Thirty-year FRMs averaged 4.19% in the same period last year, while 15-year FRMs averaged 3.36%, which represents a 34-basis-point and a 29-basis-point drop, respectively.

Mortgage rates have slid in recent months. This is the 10th consecutive week they have stayed below the 4% benchmark.