WASHINGTON — U.S. consumer prices rose just 0.1% in June, as cheaper gas prices were offset by higher rents and auto costs.

The Labor Department said Thursday that the consumer price index increased 1.6% in June from a year earlier. That is down from 1.8% in May and the second straight drop. However, excluding the volatile food and energy prices, core inflation rose 0.3% in June, the biggest increase in 18 months. It rose 2.1% from a year ago.

Inflation has been muted throughout the 10-year expansion, now the longest on record, even as the unemployment rate has dropped to a very low 3.7%. Federal Reserve Chairman Jerome Powell cited persistently low inflation on Wednesday as a justification for potentially lowering short-term interest rates at the Fed’s next meeting in late July.