The average rate on a 30-year fixed mortgage in the United States rose to 6.66 percent this week, reaching its highest level in nearly a year and placing renewed pressure on prospective homebuyers.

Freddie Mac said the rate increased from the previous week, continuing a recent upward trend. Although borrowing costs remain slightly lower than they were at the same point last year, the latest increase has weakened expectations that home financing would become significantly cheaper during the summer.

Why Mortgage Rates Are Rising

Mortgage rates do not move directly with the Federal Reserve’s benchmark interest rate. Instead, they are strongly influenced by long-term government bond yields and investors’ expectations for inflation, economic growth and future monetary policy.

When investors expect inflation to remain elevated or believe interest rates will stay higher for longer, yields on long-term US Treasury bonds often rise. Mortgage lenders generally respond by increasing the rates offered to borrowers.

This means mortgage costs can climb even when the Federal Reserve has not announced an immediate change in policy. Financial markets frequently react to expectations long before central bank officials make a formal decision.

Homebuyers Face Higher Monthly Costs

A higher mortgage rate increases the monthly cost of financing a home, reducing the amount many households can afford to borrow. Some buyers may need to consider a less expensive property, provide a larger down payment or delay their purchase.

The effect is particularly difficult for first-time buyers, who often lack the equity accumulated by existing homeowners. They are entering a market where home prices remain high while financing costs continue to limit purchasing power.

The National Association of Realtors has already reported weaker pending home sales, linking the slowdown to elevated mortgage rates and record home prices. The combination has left the housing market highly sensitive to even modest changes in borrowing costs.

High rates are also discouraging some existing homeowners from selling. Many secured mortgages at much lower rates in previous years and would face substantially higher financing costs if they purchased another property. This so-called lock-in effect can restrict the supply of homes available for sale.

The 6.66 percent figure is a national average rather than a rate offered to every borrower. Individual offers vary depending on creditworthiness, the loan structure and the lender.

A sustained decline in mortgage rates will probably require lower bond yields and clearer evidence that inflation is moving under control. Until then, expensive financing is likely to remain one of the main constraints on the US housing market.