The Labor Department said Friday that the consumer price index rose 3.4% last month compared with a year ago, the same as in July. But on a monthly basis, inflation accelerated, as costs jumped 0.4% from July to August, up from an increase of just 0.1% the previous month.

The figures show that inflation remains stubbornly elevated, more than five years after prices first soared as the economy emerged from the COVID pandemic. Persistent inflation has presented a major challenge for the inflation-fighters at the Federal Reserve and has soured many voters on the Trump administration’s economic management.

Excluding the volatile food and energy categories, core prices were 2.4% higher in August than a year ago, down slightly from July’s 2.5% and the third straight decline. But on a monthly basis, core prices rose 0.3% from July to August, the largest increase since April.