WASHINGTON — Mortgage rates edged marginally higher last week, continuing a pattern of little movement in recent weeks amid uncertainty over the effect of the delta coronavirus variant on the economic recovery.

Average rates for home loans remain historically low at under 3%. Mortgage buyer Freddie Mac reported today that the average for the 30-year mortgage ticked up to 2.87% from 2.86% last week. The benchmark rate, which reached a peak this year of 3.18% in April, stood at 2.91% a year ago.

The rate for a 15-year loan, a popular option among homeowners refinancing their mortgages, rose to 2.17% from 2.16% last week.

Worries are growing that the now-dominant delta variant is starting to cause an economic slowdown, uncertainty that has kept mortgage rates in a narrow band. In recent weeks, many economists have been downgrading their estimates of growth in the U.S. economy for this quarter and for 2021 as a whole, as the variant has sent confirmed COVID cases rising throughout the country.

A government report today showed that U.S. gross domestic product — the total output of goods and services — grew at a robust 6.6% annual rate in the April-June quarter, slightly faster than previously estimated.

Meanwhile, the number of Americans applying for unemployment benefits rose for the first time in five weeks even though the economy and the job market have been recovering briskly from the pandemic recession. Claims edged up by 4,000, to 353,000 from a pandemic low 349,000 a week earlier.