The latest inflation data is expected to show price increases are accelerating

Key points

• Economists expect September headline CPI to rise 0.6% for the month and 3.6% year over year.
• Core inflation is forecast at 0.2% monthly and 2.5% over 12 months.
• Brent crude rose more than 14% in September and traded around $105 per barrel on Tuesday.

The September consumer price index, due Wednesday, is expected to show inflation accelerating as energy costs continue to climb. Economists polled by Dow Jones forecast a 0.6% monthly increase in the headline CPI and a 3.6% rise from a year earlier, a 12-month pace that would move further from the Federal Reserve's 2% goal.

Core inflation, which excludes volatile food and energy prices, is projected to rise 0.2% from August and 2.5% year over year. That would be a slight slowdown from the prior month but an uptick on a 12-month basis.

Oil prices drive the risk

Joe Brusuelas, chief economist at the tax firm RSM, said oil-related prices could push the headline figure even higher. Energy costs have been among the biggest inflation drivers since the U.S. war with Iran began earlier this year, and President Donald Trump last week loosened diesel restrictions on Russia to boost the global oil trade, though analysts do not expect it to meaningfully lower prices.

Brent crude, the global oil benchmark, climbed more than 14% in September, lifting its third-quarter gain to about 42%, and traded around $105 per barrel on Tuesday. Brusuelas said there is "real upside risk" for the September CPI and that models typically undershoot when inflation moves like this.

We've got real upside risk on the September CPI

— Joe Brusuelas, chief economist at RSM

Pressure on the Fed

Robert Sockin, chief U.S. economist at asset manager PGIM, said sticky oil prices could raise costs for non-energy goods and services, making it harder for the Fed to dismiss the energy surge as a short-term shock that does not require rate increases. The Fed raised rates last month for the first time in three years and signaled in its meeting minutes that it will likely have to hike again; Fed funds futures traders expect the next increase at the December policy meeting, according to CME's FedWatch tool.

Sockin said the list of reasons to hike rates is long and that the firm has low confidence in the timing of the Fed's next move but more conviction on the direction of travel. Wednesday's CPI release is the last before November's midterm elections, and University of Michigan data show economic confidence has fallen across political affiliations this year, with Republican and independent voters posting steeper declines than Democrats since the start of 2026. Economists also forecast Thursday's producer price index to rise 0.6% from August to September and 5.5% over 12 months, both marking a modest acceleration from August.