U.S. consumer prices rose at a slightly slower pace in April compared to March, though persistent supply-side disruptions still kept inflation near its highest level in 40 years. And core consumer prices rose more than anticipated even while decelerating compared to March, suggesting underlying inflationary trends across the economy remained hot.

The Bureau of Labor Statistics' April Consumer Price Index (CPI) rose 8.3% in April over last year, coming down from March's 8.5% advance. That rise had marked the fastest rate since 1981. Consensus economists were expecting an 8.1% increase in April, according to Bloomberg.

On a month-over-month basis, the broadest measure of CPI increased by 0.3%, compared to March's 1.2% rise.

Heading into Wednesday's report, many economists had expected the CPI would decelerate in April compared to the prior month, showing at least tentative a sign that March was the peak rate of inflation for the year. However, the latest data showed a smaller-than-expected slowdown in inflation across both the headline and core measures.

And much of the deceleration in CPI for April came from the volatile energy component. This had been expected, since prices for crude oil, gas and other energy commodities moderated in April after spiking in March immediately following Russia's invasion of Ukraine.

And indeed, the energy price index fell 2.7% in April compared to March, after soaring by 11% during the previous month. Within this category, the motor fuel index dropped 5.8% and the gasoline index dropped by 6.1%, and energy commodities index dipped by 5.4% compared to March.

“The pace of price increases moderated, but not as much as expected. Excluding a decline in energy prices – which appears outdated by this point – the increases remain widespread," Greg McBride, chief financial analyst at Bankrate, said in an email Wednesday morning. "With the annual rate ticking down from 8.5% to 8.3, it can be tempting to say we’ve seen the peak, but we’ve also been head-faked before as was the case last August.”

And even excluding energy and the similarly volatile food category, core CPI decelerated only modestly in April compared to March. Core CPI rose by 6.2% last month over last year, following March's 6.5% increase. And on a month-over-month basis, core CPI rose 0.3%, compared to the 0.4% rate expected.

Shelter prices, considered one of the stickier price categories, rose by 0.5% on a monthly basis in April for a third consecutive month. Prices for new vehicles also accelerated markedly, jumping 1.1% for the fastest monthly rise since December. And other reopening-related categories also ramped up in April, including airline fares, which jumped 18.6% to build on March's 10.7% monthly rise.