The Consumer Price Index rose 0.4% month-over-month in August on a seasonally adjusted basis, the Bureau of Labor Statistics reported on September 11, 2026. That matched the Dow Jones consensus for the headline number but masked a more troubling detail underneath: core CPI, which strips out food and energy, climbed 0.3%, beating expectations of 0.2%.
On a year-over-year basis, headline inflation hit 3.4%, while core inflation registered 2.4%. The core figure technically dipped from July’s 2.5% annual reading, but the monthly overshoot suggests the disinflationary trend the Fed has been banking on might be losing momentum at an inconvenient time.
What drove the numbers
Gasoline did most of the heavy lifting. Energy prices surged 2.1% for the month, with gasoline alone jumping 3.9%. That single category accounted for more than a third of the total headline increase.
Food prices barely budged, rising just 0.1% month-over-month. Shelter costs, the stickiest and most closely watched component, continued their moderate upward grind.
FactSet’s median pre-release projection had pegged year-over-year headline CPI at 3.3% and core at 2.4%. The headline overshot by a tenth of a point. July’s headline reading had been a tame 0.1% month-over-month.
What it means for the Fed
The timing here matters more than usual. The Federal Open Market Committee convenes next week, and this report is one of the last major data points policymakers will digest before making their rate decision.
Shelter inflation continues to be the quiet antagonist in this story. Real-time rent trackers have shown cooling for months, but the BLS methodology captures those changes with a significant lag.
Energy volatility adds another layer of uncertainty. Gasoline prices are notoriously noisy from month to month, influenced by refinery maintenance schedules, geopolitical supply risks, and seasonal demand patterns. August’s 3.9% jump could easily reverse in September.