El Niño, the Pacific warming pattern that shifts weather around the globe, seems to have set another record weeks before forecasters expect it to peak. Australia’s Bureau of Meteorology says, in an ENSO update dated October 13, that its weekly relative Niño3.4 index reached +2.81 °C for the week ending October 11, “well above the El Niño threshold (+0.80 °C).” In the bureau’s weekly sea-surface temperature data, known as GAMSSA, which start in 2008, that marks “the highest value on record,” the bureau says, “exceeding +2.78 °C for the week ending 22 November 2015.” BBC Weather, in a piece by lead weather presenter Simon King published at 11:18 UTC (4:18 a.m. PT) on October 13, the earliest outlet report this desk found, says the bureau’s figure means average weekly sea-surface temperatures in the central Pacific “have reached their highest level on record.”

The record carries limits that the bureau spells out. The same update says: “Monthly relative Nino3.4 values remain below long-term records.” BBC Weather notes that the bureau’s weekly data reach back only to 2008, and describes the figure as significant because it now exceeds levels from the record-breaking December of 2015; the bureau itself names the week ending November 22, 2015 as the previous weekly high, so the two accounts differ on the month. The bureau calls El Niño “at near-record levels” and says both ocean and atmosphere indices reflect values consistent with a strong El Niño, “with further intensification forecast during the rest of spring” — the southern hemisphere spring.

The word “relative” matters here, according to BBC Weather. It reports that the Pacific keeps warming because of human-induced climate change, which starts to mask the strength of the natural El Niño warming, so Australian and U.S. official forecasters now use a Relative Ocean El Niño Index (RONI) to compare this event with earlier ones. NOAA’s Climate Prediction Center (CPC), in its October 8 discussion, defines a historic event as +2.5 °C or more for a three-month RONI value.

Hausfather, a climate scientist at Berkeley Earth, told the BBC: “We are currently witnessing an El Niño event that is unprecedented in the historical record.” He also said, according to BBC Weather: “The strength of El Niño this year is spilling out of the traditional El Niño region.” BBC Weather reports that he called the latest projections “astonishing” and said they would likely set new records “by a remarkable amount.” The BBC piece says the warmth now stretches well beyond the tropical region normally used to monitor El Niño, with much more widespread ocean warmth across the Pacific and into the Gulf of Mexico than in the major events of 1972-73, 1982-83, 1997-98 and 2015-16, and that scientists say long-term ocean warming explains only part of that.

Other markers point the same way, the outlets and agencies say. BBC Weather reports that scientists declared a record for daily sea-surface temperatures in the central-eastern Pacific in September, beating the previous record from the very strong El Niño of 2015, and that temperatures above 30C have appeared for the first time in parts of the tropical Pacific. India’s Down To Earth, on October 9, reported that Niño 3.4 temperatures reached 30.06°C on October 5, citing NOAA’s Optimum Interpolation Sea Surface Temperature (OISST) dataset. Japan’s Meteorological Agency, in an outlook updated October 9, says September NINO.3 sea-surface temperatures ran +4.0°C above normal, beyond the previous record of +3.6°C set in December 1997, the highest since its records began in 1949.

The numbers do not line up neatly, and they seem to come from different indices, regions and datasets. NOAA’s CPC says most Niño indices rose last month, reaching +2.1°C in Niño-3.4, +3.0°C in Niño-3 and +3.9°C in Niño-1+2, with anomalies above +4.0°C in parts of the eastern equatorial Pacific. JMA gives +4.0°C for NINO.3 in the same month. Down To Earth quotes Hausfather writing on X that “September monthly Niño3.4 anomalies also set a record at 2.9°C (beating 2015 and 1877's 2.75°C).” The WMO says Niño 3.4 anomalies climbed from an average +1.6 °C in June to +2.5 °C in August. This desk could not reconcile those figures into one series and shows them side by side.

Forecasters expect more. BOM says all models, its own included, forecast the warmth in the tropical Pacific to peak around November or December and to persist into autumn 2027, with relative Niño3.4 values forecast to pass the warmest observed since reliable records began in 1950 and “most models indicating a peak monthly value above +3.0 °C.” BBC Weather says forecasts from the European Centre for Medium Range Weather Forecasts and NOAA indicate a likely December peak. NOAA’s CPC keeps an El Niño Advisory in place and puts the chance of a historic event at 54% for September to November, 83% for October to December and 70% for November to January. The WMO, in an October 8 release on its Global Seasonal Climate Update, forecasts a seasonal Niño 3.4 anomaly of approximately +3.7°C for October to December, which it calls “the highest since observations began” and stronger than the previous record of +2.6 °C from November 2015 to January 2016. JMA says the strongest El Niño conditions look “virtually certain (100%)” to continue until boreal winter.

WMO Secretary-General Celeste Saulo said in that release: “El Niño is firmly established and strengthening rapidly. WMO forecasts indicate a near-100 per cent likelihood that it will persist through February 2027, potentially being one of the strongest since at least 1950.” She told the Global Heat Forum in Bangkok, according to the WMO: “El Niño doesn't add new heat to the planet. It releases heat the ocean has already been storing beneath the surface - which is why a strong event so often becomes one of the hottest years measured (as with 2024).” Down To Earth carries the same lines.

Global heat already runs high, the bureau says. Its update puts global sea-surface temperatures at record levels, with September 2026 the warmest September on record across 60°S to 60°N, at 1.02 °C above the 1961–1990 average, and the third-warmest month overall since 1900, behind only August 2026 and August 2023. BBC Weather says the extra heat El Niño releases, combined with human-driven climate change, looks set to help make 2026 one of the warmest years on record, with unusually high global temperatures likely to continue into 2027. On whether climate change makes El Niño itself stronger, BBC Weather reports that the WMO says it sees no current evidence of that, and BBC Weather adds that the question remains an active area of scientific research; a September 1 WMO release saved by this desk says: “El Niño is a natural climate phenomenon and is not caused by climate change.”

Impacts vary by place. BBC Weather says the strength of an El Niño does not automatically decide the scale of impacts in any one location, and recalls that the 1997-98 event brought severe drought and fires to south-east Asia and floods to parts of East Africa, while the 2015-16 event brought severe drought and wildfire activity back to parts of south-east Asia and one of southern Africa’s worst droughts in decades. It reports that the WMO says drought and flood-related disruption has already surfaced in several regions, with growing concern over food security in parts of East Africa and the Asia-Pacific. The bureau adds its own caution for Australia: “A strong El Niño signal in the Niño3.4 region does not necessarily mean strong impacts on Australian rainfall and temperature; ENSO is only one of many factors that can influence Australia’s seasonal weather and climate.” BOM also reports a 30-day Southern Oscillation Index of –20.2 to October 11, well below the El Niño threshold of –7, and an Indian Ocean Dipole index of +0.88 °C, its fifth straight week above the positive threshold, though the bureau still calls the IOD neutral. CPC’s next monthly discussion falls on November 12, and JMA’s next outlook on November 10.