Average rates for 30-year fixed-rate mortgages (FRMs) dipped slightly, setting new weekly records, while other types of mortgages varied, still hovering around historic lows. Freddie Mac's weekly survey put the average rate for a 30-year FRM at 4.57% with a 0.7 origination point for the week ending July 8. That's down slightly from last week's average of 4.58% and below the year-ago average of 5.2%. It's the third consecutive week that the 30-year FRM set a new record low in the 39 years that Freddie Mac has tracked the product. The Bankrate survey of large banks and thrifts also set a new record, with the average rate for a 30-year FRM at 4.74% with a 0.39 origination point. That's down from last week's then record-setting average of 4.75% and a year ago, when the survey averaged 5.59%. “With mortgage rates falling to historic lows, refinance activity has been strong over the past three months,” said Frank Nothaft, Freddie Mac vice president and chief economist. “The Bureau of Economic Analysis reported that the effective mortgage rate of all loans outstanding was just below 6% in the first quarter of 2010, the lowest since the series began in 1977. Since the start of the second quarter, two out of three mortgage applications on average were for refinancing, according the Mortgage Bankers Association." As HousingWire previously reported, Barclays Capital research found that Ginnie Mae constant prepayment rates rose from April to May as buyouts occurred across vintages and coupons. Freddie said the 15-year FRM averaged 4.07% with an average 0.7 point, up from last week's average of 4.04%, but below the year-ago average of 4.69%. The Bankrate average for 15-year FRMs also increased slightly, at 4.22% with a 0.39 origination point, up from 4.2% last week. Average rates on adjustable-rate mortgages (ARMs) declined this week. Freddie said the five-year Treasury-indexed hybrid ARM averaged 3.75% with an average 0.7 point, down from last week's average of 3.79% and the year-ago average of 4.82%. It's a new record low in the survey for five-year ARMs. Bankrate said average rate for a five-year ARM was 4.06% with a 0.39 origination point, down from last week's average of 4.07%. Freddie said the average rate for a one-year ARM was 3.75% with a 0.7 origination point, down from last week's average 3.8% and a year ago when it averaged 4.82%. Write to Austin Kilgore.