Global volatility has investors on edge, but there was a wee bit of a silver lining for home buyers: The average 30-year fixed-rate mortgage rate dropped to 3.84 percent, the lowest mark since May and the fifth consecutive week with a rate below 4 percent, according to a weekly survey from Freddie Mac.

How long will it last? Hard to tell. Here's one perspective from Sean Becketti, chief economist for Freddie Mac:

"Given the recent volatility, mortgage rates could change up or down significantly by the time this report is released. There are indications though that the unsettled state of global markets will make the Fed think twice before taking any action on short-term interest rates in September. If that's the case, the 30-year mortgage rate may remain subdued in the short-to-medium term, providing support for continued strength in the housing sector. Just this week, new home sales were reported to be up 26 percent year over year."

And here's a look at other rates (for the week ending August 27):

  • The 15-year averaged 3.06 percent with an average 0.6 point.
  • The 5-year Treasury-indexed hybrid adjustable-rate mortgage (ARM) averaged 2.90 percent this week with an average 0.4 point.
  • The 1-year Treasury-indexed ARM averaged 2.62 percent this week with an average 0.3 point, unchanged from last week.