July 29 CPI: Why the Headline Will Look Better Than It Is — and What the June Quarter Actually Needs to Show

On Wednesday 29 July at 11:30am AEST, the Australian Bureau of Statistics will publish two things at once: the June monthly CPI — its first release — and the June quarter underlying inflation measures, including the trimmed mean the RBA uses to set rates. The headline number will look better than it has all year. The trimmed mean may not.

Fuel prices have eased, the fuel excise was halved on 1 April, and headline annual inflation has fallen from 4.6% in March to 4.0% in May. That improvement is real, but it obscures a more uncomfortable picture. The trimmed mean — which strips out one-off effects like fuel excise cuts — rose from 3.4% in April to 3.6% in May. Underlying domestic inflation is heading the wrong direction.

Whether the 29 July data confirms that, or provides a more reassuring picture, will almost certainly determine whether the cash rate rises from 4.35% on August 11. Here is what to watch.

Why 29 July Is Different From the Usual Quarterly Release

The 29 July release is unusual in one important way. Under the ABS's monthly CPI transition, June is one of four months where the monthly CPI is published simultaneously with the quarterly underlying inflation measures. On 29 July you will get three things at once:

First, the June 2026 monthly headline CPI — its first public release. We have April and May but have not seen June yet.

Second, the June quarter trimmed mean and weighted median — the quarterly underlying measures compiled on the ABS's established historical methodology. These are the numbers the RBA's models are calibrated to.

Third, all component and city-level data for the quarter.

This matters because the quarterly trimmed mean is not simply the average of the monthly annual rates. It is compiled separately, preserving the seasonal patterns the RBA relies on. The monthly trimmed mean trend — up from 3.4% in April to 3.6% in May — gives a directional steer, but the quarterly figure will be the definitive read. It may differ from what the monthly series implies.

The Misleading Headline — What's Falling and Why

The headline number will attract the most attention. Here is why the RBA will look straight through it.

On 1 April 2026, the federal government halved the fuel excise from 52.6 cents per litre to 20.6 cents per litre. This directly reduced measured petrol prices. The effect has been dramatic in the CPI numbers:

That single policy change accounts for a large share of the headline fall from 4.6% to 4.0% over the same period. The US-Iran peace deal and the gradual reopening of the Strait of Hormuz have added to that effect — global oil prices have eased in recent months, contributing to lower fuel costs here.

Neither of these is a sign that domestic inflation is cooling. The RBA acknowledged both in its June statement — noting oil prices have "eased in recent weeks" while stating "global oil supply issues will take some time to resolve." The Board will look through the fuel-driven headline improvement. What it cannot look through is a rising trimmed mean.

The Trimmed Mean Is Going the Wrong Way

While headline inflation has fallen, the RBA's preferred measure has been rising:

The trimmed mean removes the largest price movers in both directions — including fuel. What it shows is what is happening to the middle of the price distribution: services, rents, food, healthcare, insurance. These categories are driven by wages and domestic demand, not petrol prices or Middle East supply chains.

In May, services inflation rose to 3.7% from 3.5% in April. Rents and housing costs held at 6.5% annual. Food and non-alcoholic beverages accelerated to 3.3% from 2.8%. None of these moved because of fuel. They reflect an economy where domestic price pressures remain elevated despite three rate hikes in 2026.

This is the concern the RBA flagged in its June hold statement: "inflation is likely to remain high for some time as fuel price increases pass through to other goods and services." Whether the quarterly figure confirms that the underlying trend is accelerating, or provides a more reassuring read, is the central question the 29 July release will answer.

How to Read the 29 July Result

The quarterly trimmed mean is the number that will drive the August decision. Here is how to interpret it when it drops at 11:30am on 29 July:

The Two Effects the RBA Will Look Through

Fuel Excise Cut (from 1 April 2026)

The excise halving affects the April, May, and June CPI reads — the full June quarter. It is a one-off policy effect that directly reduces measured transport inflation without reducing underlying domestic price pressure. From July 2026, this effect starts dropping out of the annual comparison base, meaning transport inflation may bounce in the second half of 2026. The RBA will not treat a June quarter headline fall driven by the excise cut as evidence that its job is done.

Strait of Hormuz Reopening

The US-Iran peace deal and the beginning of Strait of Hormuz normalisation have contributed to falling global oil prices. This feeds into Australian petrol prices over a four-to-eight-week lag. However, the RBA's Board stated in June that "global oil supply issues will take some time to resolve" — suggesting it will not declare victory on the oil shock until several more quarters of data confirm sustained easing.

The practical read: if the June quarter headline falls sharply while the trimmed mean stays elevated, the RBA will flag that discrepancy in its August statement. The trimmed mean is the number that drives the decision.

Where the Banks Stand

For the first time in this rate cycle, three of the four major banks have called the peak at 4.35%, with Westpac the sole outlier forecasting two further increases.

Westpac chief economist Luci Ellis, speaking this week: "Conviction around our expectation of an August hike has risen, subject to confirmation once the June quarter CPI data is released." On the September hike, Westpac describes it as their base case but explicitly flags it as less certain: "A September hike remains our base case — just — there are credible scenarios where the second cash rate increase occurs later or not at all."

A quarterly trimmed mean above 3.7% would likely shift CBA, ANZ, or NAB toward revising their hold calls. A reading below 3.2% would likely see Westpac abandon its two-hike forecast.

What Borrowers Should Do Before 29 July

Review your rate before the CPI, not after. If the trimmed mean comes in hot and the market moves toward an August hike, fixed rates will reprice before the RBA meeting. Variable rate reviews can also take a week or more to process. Starting now means you are ahead of the queue.

Run your budget at 4.60% and 4.85%. At a typical variable rate of 6.35%, a $600,000 25-year P&I loan currently costs approximately $3,350/month. One hike in August adds approximately $92/month to around $3,442. If Westpac's two-hike scenario plays out — August and September — repayments rise by approximately $180/month to around $3,530 by October. Know whether either of those numbers changes anything for your household before 29 July makes it relevant.

Watch the trimmed mean, not the headline. When the numbers drop at 11:30am on 29 July, go straight to the quarterly trimmed mean — not the annual headline. If the trimmed mean is at or above 3.5%, the August meeting is live regardless of what headline CPI shows.

If you are considering fixing, act before the release. Fixed rates are priced on market expectations of the future cash rate. If 29 July delivers a hawkish result, fixed rate pricing will move almost immediately. The window to lock in current fixed pricing closes when the data lands.

Sources: ABS, Consumer Price Index, Australia, May 2026; RBA, Statement on Monetary Policy, May 2026; RBA, Statement by the Monetary Policy Board, June 2026; ABS, Monthly and quarterly CPI data series methodology.