The Federal Reserve raised a key interest rate for the second time in three months on Wednesday, a signal that the principals of the banking system view the economy’s health as stable.

The hike in the federal funds rate, the short-term interest rate at which banks lend to each other, still leaves the rate below the historical norm at 0.75 to 1 percent. But the Fed said it anticipated future “gradual increases,” as the country’s economic activity and labor market improve steadily, and inflation eventually stabilizes around a target of 2 percent.