US mortgage rates have climbed for seven straight weeks for the first time in three years, placing additional strain on an already weak housing market.

Freddie Mac said in a statement on Thursday that the average rate on a 30-year fixed-rate mortgage rose to 7.4% from 7.28% a week earlier. The rate is now at its highest level since November 2023. A year ago, it stood at 6.3%.

The return of mortgage rates above 7% is intensifying America's housing affordability crisis. With less than four weeks until the midterm elections, the issue is also increasingly coming into focus. Prospective homebuyers across the country are being squeezed simultaneously by high borrowing costs and home prices that remain near record highs.

Analysts at JPMorgan wrote in a research note to clients on Wednesday: "US housing affordability remains close to the worst level since the global financial crisis, and the market has effectively frozen. Insurance and property taxes are also emerging as another affordability shock, stacking on top of high home prices and elevated mortgage rates."

Data from Zillow Group Inc. shows that the typical monthly mortgage payment on a home in September was 6.7% higher than a year earlier. That does not yet include rising property tax and insurance costs. Meanwhile, consumers are also grappling with higher prices at gas stations and grocery stores.

At current rate levels, for a $500,000 property, a homeowner's monthly principal and interest payment would be about $172 more compared with locking in a mortgage rate four weeks ago; for a $1 million property, the monthly increase would be nearly $345. This calculation assumes a 20% down payment.