August inflation lands at 3.4% and rate-hike odds jump to 90%

US consumer prices rose 3.4% in the 12 months to August, according to the latest official figures^1,5. Coverage of the same print diverged in tone: CBS News described inflation as having stayed hot in August, while the BBC and The Hill described the annual rate as holding steady^1,4,5.

Core prices did the damage. Odds of a Federal Reserve rate hike surged after prices rose faster than expected², and a monthly jump in core prices lifted the probability of a hike to 90% according to CME FedWatch³.

The labour market data released alongside it was steadier. Bureau of Labor Statistics figures showed US employers added 162,000 jobs in the prior month, with the unemployment rate unchanged at 4.1 percent⁴. The bureau published its August producer price release on Thursday, September 10, 2026⁶.

Why it matters to investors

The debate is no longer about the size of a cut. It is about whether the central bank raises rates at a meeting that markets had once expected to be an easing step^2,3. New York Fed president John Williams has framed the decision around monthly readings rather than the annual rate³.

The energy channel is explicit in the reporting. The Hill tied the August figure to the Iran war’s effect on oil prices⁴, and the BBC noted the print alongside diesel passing $6 a gallon⁵. That makes the inflation the Fed is responding to substantially a supply shock, which is the hardest kind for a rate rise to address.

It is also a credibility test for the chair. Hotter-than-expected data has turned next week’s meeting into a defining test for Chairman Kevin Warsh⁷, who indicated in a speech at Jackson Hole last month that reining in price pressures remains the Fed’s primary focus¹. As one account of the pressure put it, if you do not deliver after that big speech, people take notice².

What to watch

The first item is the decision itself and whether the 90% probability now priced is met or disappointed³. A hike delivered into an oil-driven price shock would be a deliberate choice to tighten against a supply constraint.

The second is the language around core prices, given that the monthly core jump rather than the headline rate moved the odds³. The third is Warsh’s own framing, since his Jackson Hole commitment to price stability is the benchmark against which the decision will be read^1,7.