(Bloomberg) -- Mortgage rates in the U.S. plunged to the lowest level in more than five months.

The average for a 30-year loan was 2.78% down from 2.88% last week, Freddie Mac said in a statement Thursday. It was the fourth straight weekly decline, pushing rates down to the lowest since Feb. 11.

“Concerns about the Delta variant, and the overall trajectory of the pandemic, are undoubtedly affecting economic growth,” said Sam Khater, Freddie Mac’s chief economist. “While the economy continues to mend, Treasury yields have decreased, and mortgage rates have followed suit.”

Mortgage rates have been below 3.1% since mid-April after hitting a record low of 2.65% in January. Cheap borrowing costs have have given homebuyers more purchasing power, driving the hot housing market. A shortage of homes to buy has pushed up prices and made it difficult for buyers to find affordable properties.

©2021 Bloomberg L.P.