The 5-year ARM rate set record lows this week, among other rates.

In addition, the 15-year FRM and one-year ARM also fell to new lows, with the FRM down to 3.39 percent (0.46 percent down from last year) and the ARM at 2.89 percent (a 0.61 percent drop from 2010).

The 30-year FRM, which had set record lows recently, was unchanged.

According to Frank Nothaft, the vice president and chief economist for Freddie Mac, sluggish economic data has pushed the rates down.

“Weaker economic data reports eased upward pressure on mortgage rates this week and kept them at or near all-time record lows,” Nothaft said. “The economy grew at a slower rate of one percent in the second quarter than was originally reported due to a smaller increase in inventories and fewer exports.”

Bankrate, a financial firm, urged caution when dealing with the historically-low rates.

“Many of the adjustable rate mortgages have initial interest rates so low they’re bordering on the ridiculous,” Bankrate said. “While these rates are plenty tempting for borrowers that don’t imagine being in the home more than 10 years, some of these loans are now priced in such a way that rates can only go up in the future. Be very sure about your timetable or your ability to bank the savings in the meantime, as rising monthly payments would be a virtual certainty in later years.”