An inflation gauge closely monitored by the Federal Reserve accelerated last month, showing that prices remain elevated less than a week before midterm elections in which affordability concerns have become a central issue.

Consumer prices rose 3. 6% in September from a year earlier, the Commerce Department said Thursday, up from 3. 4% in August.

On a monthly basis, prices climbed 0. 5%, up from 0. 3% in August and the highest figure since May.