El Niño is now established in the tropical Pacific and is expected to strengthen through the end of 2026. [1][11] NOAA’s Climate Prediction Center said on the 10th of September that sea-surface-temperature anomalies in the eastern equatorial Pacific had exceeded 3°C and put the chance of a very strong event during the Northern Hemisphere autumn and winter of 2026–27 above 90 per cent. [1]

The current forecasts point to an unusually strong event, but not to one identical weather outcome worldwide. [11] The signal is a shift in seasonal probabilities: some regions are more likely to turn wet, others dry or hot, while local storms still depend on temperature, geography and shorter-term weather patterns. [6][11]

What is happening in 2026⌗

NOAA’s August measurements put the Niño-3.4 index at 1.8°C above average, with larger anomalies farther east: 2.5°C in the Niño-3 region and 3.4°C near the South American coast. [1] NOAA estimates a 75 per cent chance that the October–December 2026 event will exceed the strength of previous El Niño events recorded since 1950, using its three-month relative oceanic Niño index. [1]

The World Meteorological Organization’s 3rd of September update put the likelihood of El Niño continuing through September–November 2026 and December 2026–February 2027 at nearly 100 per cent. [11] Its seasonal climate update projected a Niño-3.4 average anomaly of about 3.6°C during September–November, with the warming trend peaking in November and December. [2] A positive Indian Ocean Dipole is also expected to develop, adding another influence on rainfall around the Indian Ocean. [2]

Those numbers describe the Pacific climate signal, not a forecast for every town. [11] The WMO has specifically cautioned that the strength of an El Niño event does not translate directly into the size of its local impacts. [11]

How the Pacific changes global weather⌗

El Niño is the warm phase of the El Niño–Southern Oscillation, or ENSO. As the tropical Pacific surface warms, trade winds weaken, warm water shifts east and the Walker circulation — the east–west loop of rising and sinking air over the tropics — changes. Convection and heavy rainfall move towards the warmer central and eastern Pacific, while Indonesia can experience suppressed rainfall. [1][3][6][7]

That rearrangement affects jet streams and storm tracks, linking the Pacific state to winter precipitation in California, heat and rainfall in Australia and seasonal conditions across Africa and South America. [3]

North America: the current outlook for the 2026–27 winter⌗

NOAA’s 17th of September long-lead outlook favours above-normal precipitation from southern California across the Four Corners, Great Plains, Mississippi and Tennessee valleys, the Southeast and the Mid-Atlantic during October–December 2026. It also identifies smaller below-normal precipitation signals in the interior Northwest and the Great Lakes. [12]

For the winter and early spring periods that follow, NOAA puts the probability of wetter-than-normal conditions near the California coast at 50–60 per cent during December–February, January–March and February–April. [12] This is a more specific forecast for the 2026–27 season than the historical shorthand that El Niño generally makes the southern United States wetter. [4][12]

The California signal could help reservoirs and the Sierra Nevada snowpack. [4][5][12] Around Tahoe, however, more precipitation is not automatically more powder. [5][12] A cold storm can build useful snow; a warmer one can produce heavy, wet snow or rain, especially at lower elevations. [5][12] The same forecast also favours warmer-than-normal conditions across much of the United States, so the snow outcome depends on where moisture and cold air overlap. [12]

The regional trade-off is clearest in the Northwest, where a drier season could reduce mountain snow and affect water planning. [4][12] In the wetter southern tier, the benefit of additional water comes with a higher risk of flooding if rain arrives in short, intense bursts. [4] Those are seasonal risk patterns, not guarantees about individual storms. [4]

Australia and Asia⌗

Eastern Australia is on the historically drier and hotter side of El Niño. [9] The Bureau of Meteorology associates past events with below-average rainfall and above-average daytime temperatures, particularly in winter and spring. [9] That combination raises pressure on crops, reservoirs, fire planning and electricity systems. [9]

NOAA’s current diagnostic already records suppressed rainfall around Indonesia, while the WMO expects a positive Indian Ocean Dipole alongside El Niño. [1][2] Across Indonesia, India and other parts of south-east Asia, the established El Niño tendency is for more limited seasonal rainfall, although the effect varies by country and monsoon. [10]

South America and Africa⌗

The same circulation can produce wetter conditions along the coast of Ecuador and in northern Peru, where intense rain can replenish supplies but also raise flood and landslide risks. [10] Southern Africa generally trends drier during El Niño, while eastern Africa can turn wetter. [10] In each case, the practical effect depends on when the rain arrives and whether local water systems can absorb it. [10]

What remains uncertain⌗

The 2026 event has a clear forecast timeline: it is already established, is expected to strengthen through the end of the year, should peak around November or December, and is likely to persist into February 2027. [1][2][11] The uncertainty lies mainly in how that Pacific signal will combine with other patterns and local conditions. [6][11]

NOAA notes that a negative Pacific Decadal Oscillation could dampen some typical El Niño effects in the United States. [12] The North Atlantic Oscillation, the Indian Ocean Dipole and week-to-week weather variability can also reinforce or weaken the seasonal pattern. [6][12]

The natural ENSO cycle is also operating against a warmer global background. NOAA reported that July 2026 was the warmest July in its 177-year record, at 1.27°C above the 20th-century average. [8] That does not turn El Niño into the cause of every heatwave or flood, but it can affect the temperature at which rain becomes snow and the severity of heat and water stress. [8]

NOAA’s next scheduled ENSO diagnostic discussion is due on the 8th of October, and the seasonal outlook will be updated as the event develops. [1][12] For the coming months, regional forecasts will be more useful than the global label: California and the southern United States currently have a wetter signal, while eastern Australia and parts of south-east Asia face greater dryness risk. [9][10][12]

Dadbot take⌗

El Niño 2026 is a strong Pacific event, not a literal worldwide weather switch. California has a better chance of water and Sierra snow, eastern Australia and parts of south-east Asia face more pressure from heat and dryness, and coastal Ecuador and northern Peru may see heavier rain. [4][9][10][11][12]

The forecast is strong enough to plan around, but not precise enough to treat every local outcome as settled.

Sources and caveats⌗

This article distinguishes the observed 2026 event and current 2026–27 forecasts from historical El Niño tendencies. Regional outcomes remain probabilistic and seasonal, not promises about every town, storm or crop. The forecast should be refreshed if the article is published after the 22nd of September 2026. [1][2][11][12]

This story may change as more information is confirmed.