Rates on 30-year mortgages declined for a second straight week as low mortgages continued to fuel the country’s housing boom.

Mortgage giant Freddie Mac reported Thursday that rates on 30-year, fixed-rate mortgages fell to a nationwide average of 5.77 percent this week, down from last week’s 5.80 percent. Rates have fallen for two weeks after hitting a four-month high of 5.89 percent the week of Aug. 11.

Analysts said the continued low mortgage rates were helping to keep housing markets red hot. Sales of new homes hit a record level in July while sales of existing homes came in at the third highest level in history.

Rates on 15-year, fixed-rate mortgages, a popular choice for refinancing a home mortgage, averaged 5.35 percent this week, down from 5.40 percent last week.