Inflation remains stubbornly elevated in America and unexpectedly picked up in January, a fresh reading of the Federal Reserve’s preferred index showed, underscoring the daunting challenge facing central bankers as they try to wrestle price increases back to a normal pace.

The Personal Consumption Expenditures price measure climbed 5.4 percent in January from a year earlier, a report on Friday showed. That was more than the 5 percent economists had expected, and it is up from 5.3 percent in December, which was revised higher.

Stripping out food and fuel prices, both of which jump around a lot, the price index climbed by 4.7 percent in the year through last month, also more than expected in a Bloomberg survey of economists.

Those inflation readings are well above the Fed’s goal for 2 percent price increases. And the report’s details offered other reasons to worry: Price increases had slowed sharply on a monthly basis in recent months, but they are now showing signs of speeding back up. The overall index climbed 0.6 percent between December and January, the fastest pace of increase since last June.

The takeaway is that rapid inflation may have shown early signs of slowing, but it has not yet been defeated. Fed officials raised rates at the fastest pace since the 1980s last year in a bid to cool consumer demand and force price increases to moderate, and they have suggested in recent weeks that they may need to push borrowing costs higher than they had previously anticipated if price increases and the economy do not moderate as much as they expect in the coming months.

The report also offered a snapshot of spending — and it suggested that American consumers are still going strong.

Personal spending, which spans both goods and services, climbed by 1.8 percent in January. That compared to a slight 0.1 percent decline in December, and was more than the 1.4 percent increase that economists had anticipated. After adjusting for inflation, consumer spending rose last month.

Whether consumers keep spending is a key question as the Fed ponders its next policy steps. If demand remains robust, it could make it difficult for the economy to slow enough that businesses charge less and inflation eases fully back to normal.

Central bankers have raised interest rates from near zero at this time in 2022 to more than 4.5 percent as of this month. Officials signaled in December that they might need to ultimately lift rates to just above 5 percent, but those estimates have crept slightly higher. And key policymakers have been clear that if the economy fails to slow as expected, they will do more.

Higher interest rates weigh on the economy by making it expensive for households to borrow to buy a car or purchase a house, and by making it pricier for businesses to finance expansions. As those transactions stall, the aftershocks trickle through the economy, slowing not just the housing and automobile markets, but also the labor market and retail and services spending as a whole.

But the full effect of policy takes time to play out, which makes it difficult for central bankers to assess in real time how much policy tightening is exactly the right amount to slow the economy and bring inflation to heel.

Fed officials will be parsing an array of data — on jobs, spending and inflation — before their next meeting on March 21-22.

They may also take a signal from recent earnings calls, which have suggested that the economy is beginning to lose some of its hotness, though it is still not fully back to normal. Corporate profit margins had expanded drastically, but could begin to stall out as firms find it increasingly difficult to charge ever-higher prices.

In 2022, “we observed a resilient customer who is less price sensitive than we would have expected in the face of persistent inflation,” Ted Decker, Home Depot’s chief executive, said on a call with analysts this week. But “we noted some deceleration in certain products and categories, which was more pronounced in the fourth quarter.”