August CPI Friday: Fed's Last Data Point Before Rate Vote
August CPI prints Friday at 8:30 AM ET — nowcasts show 3.38% YoY re-acceleration. Here's what it means for the Sept 15–16 FOMC decision.
Key Points
- Inflation nowcasting as of September 4 projects August headline CPI re-accelerating to +3.38% YoY and +0.36% MoM — up from July's +3.4% annual reading but a meaningful jump sequentially.
- Three Fed hawks — Hammack, Kashkari, and Logan — already dissented in favor of a 25 bps hike at the July 29 meeting, meaning Friday's print lands in a room already primed to move.
- A CPI print at or above 3.38% YoY on Friday, September 11, materially raises the probability of a surprise rate hike at the September 16 FOMC decision; watch the 10-year yield and TLT for the market's immediate verdict.
Friday's August CPI report — hitting the tape at 8:30 AM ET on September 11 — is the single most important data release of the week, and arguably of the month. With the Fed's blackout period already in effect and the September 15–16 FOMC decision just four trading days away, this print is the last number policymakers will see before they vote. Inflation nowcasts are pointing to re-acceleration. Three sitting FOMC members already wanted to hike in July. The setup is as live as it gets.
What the Nowcast Is Telling Traders
The numbers on the table are not benign. As of September 4, inflation nowcasting models project August headline CPI at +3.38% year-over-year and +0.36% month-over-month — a sharp sequential jump from July's +0.1% MoM print, driven primarily by energy. July's annual headline reading came in at +3.4%, meaning the YoY number isn't dramatically different, but the monthly acceleration is the signal worth watching. A +0.36% MoM print would be the hottest sequential gain since early 2025, and it arrives at exactly the wrong moment for a Fed trying to hold the line at 3½ to 3¾ percent.
Core CPI, which strips out food and energy, is projected to come in at +2.38% YoY and +0.20% MoM for August — essentially unchanged from July's +2.5% annual and +0.2% monthly readings. That relative stability in core provides the doves on the committee with their counterargument: underlying demand-side inflation remains contained near 2.5%, and the headline acceleration is a commodity story, not a wage or shelter story. But with energy up +14.7% over the 12 months through July and no evidence that oil markets are cooling into autumn, the "transitory supply shock" framing is wearing thin on the hawks.
The energy component is the arithmetic center of this story. The BLS CPI data through July showed energy up nearly 15% on a 12-month basis. If August energy prices held even roughly steady versus July, that base effect alone pushes the headline print higher. Food, up 3.0% through July, adds a secondary layer of pressure on lower- and middle-income households — politically sensitive context that the Fed does not officially target but cannot ignore when calibrating communication around a potential hike.
The Fed's Problem
The Fed is in its blackout period as of Saturday, September 5, and will not speak publicly again until Chair Powell's post-decision press conference on September 16. That silence matters because the last policy signals from the committee were anything but unified. At the July 29 FOMC meeting, three members — Cleveland Fed President Beth Hammack, Minneapolis Fed President Neel Kashkari, and Dallas Fed President Lorie Logan — voted to raise the federal funds rate by 25 basis points. They were outvoted, but three dissents on a hold vote is a significant show of hawkish force. The committee held at 3½ to 3¾ percent, citing "elevated uncertainty" tied partly to the ongoing Middle East conflict, but the July statement was explicit that inflation "remains elevated relative to the Committee's 2 percent goal, in part reflecting supply shocks that have driven price increases in certain sectors, including energy."
That language was drafted before the August nowcast data existed. If Friday delivers a headline at or above 3.38% — let alone a surprise print north of 3.5% — those three dissenting hawks have a stronger case, not a weaker one. The question for September 16 is whether any of the voters who held in July move to join Hammack, Kashkari, and Logan. It only takes one. A 4-vote hawkish bloc would not constitute a majority on the 12-member voting committee, but a shift to even 5 or 6 votes for a hike would represent a dramatic repricing event across rates, the dollar, and equity multiples.
Real average hourly earnings through July were down 0.2% year-over-year — workers are losing ground to inflation in purchasing power terms. That's a politically and economically uncomfortable backdrop that the Fed acknowledges in its dual mandate, but it cuts both ways: weak real wages argue for caution on tightening further, but persistent above-target inflation with negative real wage growth is precisely the stagflationary scenario the Fed is most anxious to avoid embedding in expectations.
What Traders Watch Next
The 10-year Treasury yield and the TLT long-bond ETF are the instruments to watch at 8:30 AM ET Friday. A headline CPI print at or above the nowcast's 3.38% YoY will likely push the 10-year yield sharply higher as markets rapidly reprice September hike odds from what has been a baseline assumption of a hold. A miss to the downside — say, a headline print of 3.1% or lower driven by surprise energy disinflation — would reinforce the hold, compress yields, and provide relief to rate-sensitive equities. The binary is clean, which makes this one of the more tradeable macro events of the quarter.
Thursday's August PPI data at 8:30 AM ET provides the warm-up act. July PPI final demand was unchanged month-over-month, with goods falling 0.7% and services rising 0.2%. A hot August PPI — particularly in services, which feed more directly into core PCE — would pre-position traders defensively ahead of Friday's CPI and could itself move yields Thursday morning. July import prices fell 0.4% and export prices dropped 1.3%, offering some disinflationary signal on the goods side, but the energy component of PPI will be the tell.
The critical date is Friday, September 11, 8:30 AM ET. Traders who want a clean read on September 16 need to have their positioning set before that number hits. A headline CPI at or above 3.38% YoY, combined with the three existing hawkish dissents documented in the July FOMC minutes, sets the table for the first surprise Fed hike since this tightening cycle resumed — and the 10-year yield breaking above its recent range would be the first confirmation that markets are pricing it.
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