The average rate on 30-year fixed home loans increased to 6.72% for the week ending July 10, up from 6.67% last week.

The average rate on a 30-year U.S. mortgage rose for the second week in a row, another setback for the U.S. housing market, which is mired in a sales slump as affordability constraints shut out prospective homebuyers.

Mortgage rates turned upward this week after falling the previous five weeks in a row. The 30-year fixed-rate mortgage averaged 6.78% APR, up four basis points from the previous week's average, according to rates provided to NerdWallet by Zillow. A basis point is one one-hundredth of a percentage point.