Australia · September 28, 2026

El Niño Keeps Strengthening. Australia's West and Centre Are Forecast Wet.

The Bureau's 24 September outlook favours above-average October to December rain across most of Western Australia, South Australia outside the south-east, and inland Queensland, with below-average rain in southern and eastern Victoria, Tasmania and the far north. The split is not new: it has been in the Bureau's outlooks since early August. What it means for Australian grain differs sharply by state, and it matters more for the summer crop than the winter one.

By Christopher W. Corwin · IAMElNino.com · 11 min read
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61 Mt
ABARES forecast for Australia's 2026-27 winter crop. A 12% fall year on year, and a 12% upward revision from its own June report. Both figures are in the same document.
22.8 Mt
Western Australia's share, 37% of the national winter crop, and the state where ABARES says timely in-crop rain still matters to yield.
+2.1°C
Weekly relative Niño 3.4 anomaly, week centred 16 September 2026, NOAA CPC. Niño 1+2 +3.9, Niño 3 +3.0, Niño 4 0.0.

El Niño is strengthening, and the Bureau of Meteorology's rainfall outlook for Australia does not look like the continent-wide drought the phrase usually summons. The long-range forecast issued on 24 September 2026 favours above-average rain across most of the west and centre for October to December, and puts the below-average signal in a smaller area than the shorthand implies.

Two things need separating before that reads as either good news or a forecast failure. The split is not a development from last Thursday. And it is a forecast of rainfall, not a crop result: much of this season's crop potential was established over winter, but spring weather can still move both yield and harvest quality.

What the 24 September outlook says

From the Bureau's own text, product IDCKOATCO2. October to December rainfall is likely, at a 60% to greater than 80% chance, to be above average across most of Western Australia, South Australia except the south-east, the southern two-thirds of the Northern Territory, western and southern Queensland, and north-east New South Wales. There is also a 50 to 80% chance of unusually high rainfall across much of southern and central Western Australia, which the Bureau defines as the wettest 20% of October to December records between 1981 and 2018.

Below-average rainfall is likely, at a 60 to 80% chance, for much of southern and eastern Victoria, Tasmania, northern parts of the Northern Territory's Top End, and Cape York Peninsula. For much of eastern Australia the chances are roughly equal either way.

October on its own carries a broader dry signal: for that month the Bureau gives 60% to greater than 80% odds of below-average rainfall across much of the Northern Territory, Queensland and south-east Australia. That is not in conflict with the three-month wet signal. The two are probabilities for different averaging periods over partly different areas, and the outlook does not say when within October to December the seasonal rain would fall.

The split is seven weeks old, not four days old

The Bureau keeps a one-line summary of every issue. Above-average rain in the west first appears in that archive on 9 July, for the north-west. By 6 August it reads "above average across much of the west," and it has read some version of that in every issue since. The pattern being described as new this week has been in the product for nearly two months.

What did move is worth reading precisely. Comparing the last two issues, both covering the same October to December window:

October to December17 September24 September
Overview line"below average in the south-east""below average in the south-east and far north"
Wet signal, South AustraliaWhole stateExcept the south-east
Wet signal, QueenslandWesternWestern and southern
Wet signal, New South WalesParts of the northNarrowed to the north-east
Dry signal detail"Much of the south-east and parts of the far north"Named: southern and eastern Victoria, Tasmania, northern Top End, Cape York
October-alone dry signalIncluded far south-west WAFar south-west WA removed, south-east Australia added

The last row is the one with money attached. Note also that these are the Bureau's written region names. The forecast itself is a set of shaded probability maps, and prose descriptions cannot establish whether any particular cropping district falls inside or outside a shaded area. Nothing below assigns a signal to a district the Bureau does not name.

What this means for grain, state by state

ABARES released its September crop report earlier this month at a national winter crop of 61 million tonnes. Its state results and the Bureau's regional signals line up like this.

StateWinter cropYear on yearRevised from JuneBureau signal, Oct-Dec
Western Australia22.8 Mt−16%+6%Above average, unusually high in the south and centre
New South Wales13.1 Mt−30%+12%Above average in the north-east, roughly equal elsewhere
Victoria11.3 Mt+12%+18%Below average in the south and east
South Australia11.3 Mt+24%+24%Above average except the south-east
Queensland2.2 Mt−44%−9%Above average in the west and south, below on Cape York

Victoria is the only major cropping state substantially inside the below-average area, and ABARES has already assessed that. Mild winter temperatures and early sowing into moisture have put Victorian and South Australian crops three to four weeks ahead of normal. ABARES writes that Victorian crops are "well positioned to withstand forecast below average rainfall until harvest and in some cases would benefit from a dry spell," and that in South Australia "the exceptional condition and advanced development of most crops mean that they will be more resilient to heat stress later in the season." For both states the risk ABARES actually names is a late frost on an unusually advanced crop, not drought. That risk is live until harvest.

Western Australia is the state where the rainfall forecast still bears on yield. It is 37% of the national winter crop and a third of the national wheat crop at 10.0 million tonnes, and ABARES left it with an explicit condition: soil moisture is below average in the Albany and southern Kwinana regions, where "current yield expectations are highly reliant on timely in crop rainfall to be realised." ABARES worked from the Bureau outlook issued 20 August, which gave south-western cropping regions a 25 to 40% chance of exceeding median rainfall.

IAMElNino.com analysis. The outlook now covering Western Australia's finish is wetter than the one ABARES used, which on its face is favourable for the condition ABARES set. Two caveats belong with that. ABARES quoted a September to November outlook and the current one runs October to December, so part of the difference is the calendar advancing rather than the model changing its mind; the clean like-for-like evidence is the 17 to 24 September change, both October to December, which removed far south-west Western Australia from the October dry signal. And the direction is not purely positive: an October to December wet signal spans the end of grain fill and the start of harvest, and a 50 to 80% chance of rainfall in the wettest quintile is a harvest-quality question as much as a yield one. The Bureau's maps carry no information about when within the three months the rain falls, which is the only thing that would settle it.

The outlook bears harder on the summer crop

The part of ABARES' report most exposed to this forecast is not the winter crop at all. ABARES forecasts summer crop production down 25% to 3.4 million tonnes, with area down 17%, and attributes that partly to "a relatively neutral chance of exceeding above average spring rainfall across key summer cropping regions." It then names the upside explicitly: in Queensland "the sorghum planting window is quite wide, so there is a chance that a late plant could go in if sufficient rainfall is received," and in New South Wales, "if spring rainfall is better than expected, it is possible that those growers who forewent a winter crop will plant sorghum."

Those planting decisions are still open. The Bureau now favours above-average October to December rain in western and southern Queensland, but its October-only outlook is dry across much of the state. Rain would need to reach the relevant fields in time; a wetter three-month total alone would not establish that more sorghum was planted. ABARES' December report should give a clearer estimate.

Two 12 per cent figures in one report

Worth flagging for anyone quoting the crop report. It contains two 12% figures that point in opposite directions. ABARES writes that winter crop production "is forecast to fall by 12% to 61 million tonnes in 2026-27," a year-on-year comparison, and also that production "has been revised up 12% compared to the June 2026 Australian crop report," a comparison against its own earlier forecast. Both are correct and the coincidence is genuine.

Which one belongs in a sentence depends on the question being asked. Our own Market Watch 5 used the revision figure and labelled it as a revision from June, which is the right one for a piece about a forecast improving. A reader comparing this season with last season wants the other.

The Indian Ocean is the hypothesis, not the explanation

The Bureau says it directly, in the same document that calls El Niño "well established and continues to strengthen": "A strong El Niño signal in the tropical Pacific does not necessarily mean strong impacts on Australia's rainfall and temperature; ENSO is only one of many factors."

A positive Indian Ocean Dipole is what historically accompanies a dry Australian spring across the south and east during El Niño, as in 2023. On 8 July we called the IOD the single biggest swing factor, with the index then at −0.02°C and the Bureau's models expecting a positive event during the southern hemisphere winter. We wrote that if it stayed weak or arrived late, the outlook would be "closer to a garden-variety El Niño drying signal."

Winter ended on 31 August without one. In the Bureau's Southern Hemisphere Monitoring issue of 15 September, the IOD index for the week ending 13 September reads +0.65°C, above the +0.4°C positive threshold, but the Bureau is explicit that this follows four weeks in the neutral range and that "this one observation does not indicate that a positive IOD is underway." Its summary still classifies the IOD as neutral.

That is the branch we flagged in July, and it is a reasonable hypothesis for why the outlook does not look like a classic El Niño dry spring. It is not a demonstrated explanation. The Bureau attributes its forecast to its ACCESS-S model rather than to any single driver, and it lists several: a neutral IOD, a strengthening El Niño, and Australian-region sea surface temperatures running warm, particularly to the west, which it notes "can enhance atmospheric moisture and energy that can fuel storms and rain systems." We are offering the missing-amplifier reading as the thing to test, not as the answer.

One trap for anyone checking the Pacific numbers. The Bureau reports a relative Niño 3.4 of +2.51°C for the week ending 13 September against a stated El Niño threshold of +0.80°C, while NOAA's Climate Prediction Center reports +2.1°C for the week centred 16 September. Both are labelled relative, the thresholds differ and the weeks differ, so the values are not interchangeable. This site quotes CPC throughout, including on the teleconnections dashboard.

What would confirm or refute this. Not whether the Bureau revises its outlook. An outlook that moves is a forecast updating, and it would say nothing about whether this piece reported the 24 September issue accurately. Two things are genuinely testable. The rainfall itself: the Bureau's monthly and seasonal rainfall analyses for October, November and December will show whether above-average totals actually fell across Western Australia, South Australia and inland Queensland, and whether southern and eastern Victoria and Tasmania came in below average. If most of Western Australia records below-average October to December rainfall, the forecast reported here missed. The IOD hypothesis: if the weekly IOD index establishes a sustained positive event through October and the west still records above-average rain, the missing-amplifier reading offered above fails and something else is doing the work. If a positive IOD establishes itself and the west turns dry, the conventional relationship held.

What to watch

A strong El Niño and a regionally split Australian outlook are both true at once, and the Bureau says so itself. The dry signal is real but sits mostly on crops that are advanced enough to finish without much more rain. The wet signal sits on the state whose yield is still open, and it could affect summer-crop planting if timely rain reaches those regions. What happens next is an observation, not an inference, and it starts arriving with October's rainfall.

Data vintage. Bureau of Meteorology rainfall and temperature wording is quoted from the long-range forecast issued 24 September 2026 and from the archived 17 September and 6 August 2026 issues of the same product. Those are the Bureau's text summaries; the forecast itself is a set of shaded probability maps, which were not inspected here, so no rainfall signal is assigned to any cropping district the Bureau does not name in writing. IOD and Niño 3.4 figures attributed to the Bureau come from its Southern Hemisphere Monitoring issue of 15 September 2026, covering the week ending 13 September, which was the current issue on the Bureau's site when this was written; a later issue may supersede it. Crop figures are ABARES forecasts, not measured production, from the Australian Crop Report of September 2026, No. 219, whose own quoted Bureau outlook was the one issued 20 August 2026 for September to November. The weekly relative Niño values are NOAA CPC for the week centred 16 September 2026 and are not interchangeable with the Bureau's relative index. Nothing here is a crop forecast, a yield estimate or investment advice.

Sources

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