Inflation rate in Australia: 4.3% in September, up from 4.0%

What happened. On 28 October at 11:30 AEDT, the ABS published the Consumer Price Index for September 2026. Over 12 months it rose 4.3%, against 4.0% in August. In the month, it rose 0.8% before seasonal adjustment and 0.6% after. Per ABC, the figure came in higher than expected.

Underlying inflation. Trimmed mean, a measure that cuts out the sharpest price swings, was 3.6% over the year. In August it was 3.5%: the ABS revised it down from 3.6% after a change in seasonal factors. The weighted median was 3.4% for the year. Per ABC, trimmed mean rose 1.0% in the September quarter, while the RBA had forecast 0.8% in August.

What pushes prices up. Transport rose 8.7% in a year and automotive fuel 23.6%. In September alone, fuel rose 9.4% on higher world oil prices. Housing rose 5.2%: electricity is up 12.8%, largely because Commonwealth electricity rebates ended during the year, new dwellings are up 4.7% and rents 3.6%. Games, toys and hobbies rose 15.5%, which the ABS ties to higher prices for memory and storage components.

Where it is calmer. Food and non-alcoholic beverages rose 3.2%. Clothing and footwear rose 0.4%. Services overall rose 4.1% in a year and goods 4.6%.

What people say about rates. Per ABC, the RBA already raised rates in September. KPMG chief economist Brendan Rynne called the data the last piece needed for a fifth rise this year. Betashares chief economist David Bassanese expects a rise next week and then a pause in December. RBA deputy governor Andrew Hauser said inflation was broadly in line with the bank's expectations but too high. The RBA announces its decision on Tuesday next week, together with updated forecasts.

What it means outside Australia. The country shows a chain seen elsewhere too: dearer oil reaches fuel fast, then the prices of much else. ABC links the higher prices of memory and storage to AI-driven demand for chips.

What we don't know. What exactly the RBA decides, and how the bank reads inflation in its new forecasts. We also don't know whether oil prices will hold. This is an overview of the data, not a forecast or advice.

Confirmed facts

• Australia's Consumer Price Index rose 4.3% in the 12 months to September 2026, up from 4.0% in the 12 months to August.^[1]
• Trimmed mean inflation was 3.6% in the 12 months to September 2026; August was revised from 3.6% to 3.5% after a change in seasonal factors.^[1]
• In September the CPI rose 0.8% in original and 0.6% in seasonally adjusted terms. The weighted median was 3.4% for the year.^[1]
• The release came out on 28 October 2026 at 11:30am AEDT. The next release, for October 2026, is due on 25 November 2026.^[1]
• Transport rose 8.7% in a year and automotive fuel 23.6%; in September fuel rose 9.4% on higher world oil prices.^[1]
• Housing rose 5.2% in a year: new dwellings +4.7%, electricity +12.8% (largely due to the end of Commonwealth rebates), rents +3.6%.^[1]
• Games, toys and hobbies rose 15.5% in a year, driven by higher prices for memory and storage components.^[1]
• Food and non-alcoholic beverages rose 3.2%, clothing and footwear 0.4%, services 4.1% and goods 4.6% in a year.^[1]
• Inflation rose more than expected; markets put the chance of a 0.25 percentage point RBA rate rise next week at about 85%, per Bloomberg data.^[2]
• The RBA targets inflation of 2-3%; it already raised rates in September, and KPMG says the next rise would be the fifth this year.^[2]
• Trimmed mean rose 1.0% in the September quarter against an RBA forecast of 0.8% (per the Betashares economist).^[2]
• RBA deputy governor Andrew Hauser said inflation was broadly in line with the bank's expectations but too high.^[2]
• The RBA board meeting starts on Monday and the decision comes on Tuesday, with updated forecasts.^[2]

Implications

• ConfirmedInflation in Australia is above the RBA's 2-3% range, and the headline and underlying rates both rose from August.
• ConfirmedHousing and transport, including electricity and fuel, pull the headline number up most.
• Our readingThe RBA decision next week does not rest on these figures alone, but markets already price in a rate rise.
• Our readingDearer oil and chip demand may have a similar effect in other countries that import a lot.

Still unknown

• The RBA decision next week and its new inflation forecasts.
• Whether world oil prices, which lifted fuel in September, hold.
• What the October ABS release on 25 November 2026 will show.

Who it affects

Australia, World. People who follow inflation, central bank rates and fuel prices, and Australians with a mortgage or a rent

Sources

1. Australian Bureau of Statistics: Consumer Price Index, Australia, September 2026 October 28, 2026 · official
2. ABC News (Australia): Inflation rate rises to 4.3 per cent in September, raising rate hike expectations October 28, 2026 · media