According to Zillow lender marketplace data for Wednesday, August 19, 2026, the average 30-year fixed mortgage rate increased by two basis points to 6.55%. Meanwhile, the 15-year fixed rate fell seven basis points to 5.87%, and the 5/1 adjustable-rate mortgage (ARM) decreased eight basis points to 6.31%. Rates have remained surprisingly calm this week despite recent bond market volatility.