ABC says 2026 is on track to be Australia’s wettest El Niño year on record. A very wet February and March, a September that was dry across the east, and a record that depends on definitions sit behind the claim.
ABC reported on 17 October that 2026 is on track to be Australia’s wettest El Niño year on record, with storms soaking the east. The Bureau of Meteorology’s numbers give a more textured picture. Winter was 8% above average. September was 17% below average nationally, with New South Wales and the Murray-Darling Basin among the driest on record and Western Australia the second wettest. And 75% of the year’s rain so far fell between January and April.
Our reading: a wet national calendar year can coexist with serious regional dryness during El Niño. The rain is real. What needs care is the label, because a year is not over until December and the answer depends on how an El Niño year is defined.
| September 2026 | Rain, mm | Against average | Rank of 127 (1 is driest) |
|---|---|---|---|
| Australia | 13.6 | −17% | 62 |
| New South Wales | 7.1 | −80% | 4 |
| Murray-Darling Basin | 6.8 | −80% | 2 |
| Victoria | 26.2 | −59% | 6 |
| Queensland | 3.8 | −70% | 23 |
| Western Australia | 25.3 | +147% | 126 |
September was 13.6 mm nationally. The east carried the dry: New South Wales had its fourth-lowest September on record, the Murray-Darling Basin its second-lowest, Queensland was 70% below average and Victoria had its sixth-lowest. Tasmania was driest for September since 2015. Western Australia had 25.3 mm, the second-highest September on record, behind 1904. The Bureau also reported the highest September minimum temperature on record. September was dry across eastern Australia, consistent with the usual El Niño tendency. ABC’s August piece puts that tendency at winter rainfall down 32% and spring down 20%, on average, across 16 moderate-to-strong El Niño events compared with neutral years. The observations alone do not establish the cause of any one month.
That east-dry, west-wet split matches the Bureau outlooks covered in our 28 September post. Since then ABC reports a stalled high drawing moisture onto the east coast, with more than 100 mm in Sydney in the week to 17 October and possibly more than 100 mm in Queensland’s Maranoa and Warrego districts. We have not checked those totals against station data.
Winter rainfall was 68.3 mm, 8% above average and 86th of 127. That was wetter than expected: AuctionsPlus reported that the Bureau’s 4 June outlook gave 60% to 80% odds of below-average winter rain across south-west Western Australia and central and eastern regions south of the tropics. South Australia ran 72% above average, its sixth-wettest winter on record. On the Bureau’s own list of El Niño events, taking the first year of each, 2026 is the fifth wettest winter of 29, behind 1951 at 79.3 mm, 1993 at 74.1, 1957 at 71.4 and 1991 at 71.3. ABC calls it the wettest El Niño winter in 35 years. The Bureau lists 1993 to 1994 as an El Niño event, and under this post’s rule 1993 was wetter, so the 35-year figure holds on that list only if 1993 is set aside. ABC does not say which list or rule it used, so this is a difference in comparison method, not evidence that ABC’s method is wrong.
| 2026 period | National rain, mm | Against 1961 to 1990 | Rank of 127 (1 is driest) |
|---|---|---|---|
| January | 72.5 | −10% | 62 |
| February | 127.6 | +66% | 123 |
| March | 106.6 | +69% | 120 |
| April | 17.4 | −43% | 34 |
| May | 28.0 | −4% | 85 |
| June to August | 68.3 | +8% | 86 |
| September | 13.6 | −17% | 62 |
| January to September | 434.0 | Not calculated | Not calculated |
Summed, January to September is 434.0 mm (this site’s arithmetic from rounded monthly and seasonal values). January to April supplied 324.1 mm, or 75%, and May to September 109.9 mm. February and March were each more than 60% above average. NOAA’s Oceanic Niño Index for the three-month windows ending in February, March and April was −0.39, −0.21 and +0.11, then +0.46 and +0.95 for the windows ending in May and June. Those windows overlap, so no single month marks an onset, but the wet start came while the Pacific was near neutral. ABC’s August piece credits a La Niña phase earlier in the year for the February to March rain.
ABC’s 17 October piece says none of 27 previous El Niño years since 1900 had above-average winter to spring rainfall, and that 2026 is on track to be the first. It names no dataset, baseline or list of El Niño years, and quotes no one. Its 22 August piece, which quoted Bureau senior climatologist Zhi-Weng Chua, made the same record claim then, with national rain of more than 400 mm to that date. So 17 October extends a two-month-old claim, and moves the story from our September forecast post to an observed year.
There is a way to check the list. The Bureau publishes the events it recognises, listed by pairs of years such as 2015 to 2016. Taking the first year of each, the Bureau’s national annual series reproduces both ranges ABC quoted: 319.5 to 444.9 mm for the early-20th-century events (1902 to 1925) and 436.7 to 482.1 mm for 2006, 2009, 2015 and 2023. That suggests ABC used the Bureau’s list and first years, though it does not say so.
No source we read gives a measured share. The Bureau’s 15 October outlook says a strong El Niño is underway and likely to peak around November to December as a very strong event, and that a strong El Niño does not necessarily mean strong impacts on Australian rainfall and temperature, because ENSO is one of several influences. It says the Indian Ocean Dipole is neutral, but weekly values have been above the positive threshold for five consecutive weeks, with a positive event likely to develop in spring and persist into early summer, strength uncertain. Waters around most of Australia’s west, south and south-east were up to 3°C above average in the week to 11 October.
ABC offers two candidates and says the causes remain uncertain: a large mass of warm water in the central Indian Ocean near 20°S feeding moisture into the westerlies, and an El Niño whose warmth sits near South America rather than the central Pacific, a pattern ABC says has had less effect on Australia than central Pacific events. Those are hypotheses, and we found no attribution study. For the dry-side risks, see our Indian Ocean Dipole post and The Dry Ledger.
On the Bureau’s list, taking the first year of each of its 28 events since 1902, the wettest El Niño year is 1997 at 514.2 mm. At 434.0 mm through September, 2026 needs about another 80 mm in October to December to pass it.
| Year used | Bureau-listed El Niño event | National rain, mm |
|---|---|---|
| 1997 | 1997 to 1998 | 514.2 |
| 1993 | 1993 to 1994 | 488.0 |
| 2006 | 2006 to 2007 | 482.1 |
| 1941 | 1941 to 1942 | 480.4 |
| 1963 | 1963 to 1964 | 475.6 |
| 2023 | 2023 to 2024 | 473.1 |
| 1977 | 1977 to 1978 | 469.9 |
| 2026, January to September only | Current event | 434.0 |
The rule matters. Using the second year of each event instead would rank wetter years such as 1998 at 548.9 mm, 1973 at 641.1 and 2010 at 683.7, each the start of a La Niña event on the Bureau’s list. Whether such years count is the definitional question ABC does not address. A year-to-date total also cannot be ranked against full years until December.
We cannot say which list or rule ABC used, only that the Bureau’s list with first years reproduces its quoted ranges. We have not independently verified ABC’s claim that none of its 27 previous El Niño years had above-average June to November rainfall. The 2026 season remains unfinished. We cannot attribute any month’s rain to El Niño or against it. And ABC’s forecast of a wetter-than-normal November across most of Australia is its own reading: the Bureau’s 15 October outlook names regions, with a wet signal strongest across the west and north and drier odds for southern Victoria and Tasmania.
Our reading. Australia is having a wet year, and that is a fact about the rain, not yet a record about El Niño. The wet came largely in February and March, the winter margin was modest, and September was dry across the east and exceptionally wet in the west. The record turns on a definition and on the last three months. If 2026 passes 514 mm, the careful sentence is that it was the wettest year in which a Bureau-listed El Niño began, not proof that El Niño made it wet.