Six-month certificates of deposit reached a high of 17.98 percent in August 1981, according to Ally Bank. Because the U.S. Federal Reserve keeps the short-term interest rate close to zero, as of 2015, returns on CDs remain low as well.
When the Federal Reserve maintains short-term interest rates low, mortgage rates, interest on auto loans and credit card rates stay low. Although this is good for people buying products on credit, returns on money-market accounts and CDs remain low as well. As of September 2015, the nationwide average rate of return for a one-year CD is 1.09 percent, reports Bankrate.