As of mid-to-late August 2026, a powerful El Niño is underway in the tropical Pacific and is widely expected to rank among the strongest—or the strongest—on record. Forecasters and climate models refer to it as a “Super El Niño” (sometimes called a “Godzilla” event) because sea-surface temperature anomalies in the Niño 3.4 region are projected to reach or exceed +2.0°C and, in many ensemble forecasts, approach or surpass +3.0°C during the peak in late fall and early winter. 

NOAA’s Climate Prediction Center and the International Research Institute for Climate and Society (IRI) assign very high probabilities (greater than 90% in recent updates) that this very strong event will persist through the Northern Hemisphere winter of 2026–27 and into early spring 2027. Model agreement is unusually strong, with the large majority of dynamical and statistical models pointing to peak intensity in the October–December or November–January period. 

What a Super El Niño Typically Means for the United States

El Niño shifts the jet stream. A stronger, more active Pacific jet stream tends to steer storms farther south across the southern United States while the northern tier of the country experiences a reduced frequency of Arctic air masses. The result is a classic pattern of milder conditions across the northern Plains, Upper Midwest, and Great Lakes, paired with a more active southern storm track.

Expected Impacts on Iowa’s Winter 2026–2027

Iowa sits firmly in the northern-tier zone that historically sees the clearest signal during strong El Niño events:

•  Temperatures: Above-normal temperatures are favored. Strong El Niño winters in Iowa have frequently averaged 1–3°F (or more) milder than normal, with fewer prolonged Arctic outbreaks. Sharp cold snaps can still occur, but they tend to be shorter-lived. Analog years and composites of very strong events since 1950 consistently show this warmth signal across the state. 

•  Snowfall: Seasonal totals are more likely to run below average. The southward-shifted storm track reduces the frequency of major snow-producing systems over Iowa. While individual storms can still deliver significant snow (especially early in the season when cold air is available), overall accumulation often ends up 5–10 inches or more below normal in many locations. Variability remains high—some strong El Niño winters have produced near- or above-normal snow.

•  Precipitation: Total liquid-equivalent precipitation is more variable. Fall can trend wetter, and some strong events have carried moisture into winter. However, the dominant winter pattern often features fewer widespread storm systems over the Upper Midwest, leading to near-normal or slightly below-normal precipitation for parts of the season. Early spring moisture could still raise flooding concerns if snowmelt from farther north coincides with rain.

Recent long-range outlooks and composites for very strong El Niño events align with these historical tendencies: a warmer northern tier, an active southern storm track, and reduced routine snowfall opportunities across the Upper Midwest and northern Plains, with Iowa near the southern edge of the strongest below-normal snow signal. 

Important Caveats

Even the strongest El Niño does not guarantee identical weather everywhere. Local and shorter-term patterns (the polar vortex, Madden-Julian Oscillation, and other atmospheric modes) can still produce cold or snowy stretches. Past strong events (such as 1982–83, 1997–98, and 2015–16) delivered generally mild winters in Iowa but were not completely free of wintry weather.

Farmers and residents should watch for potential effects on spring planting conditions if late-winter or early-spring moisture increases, and for the possibility of reduced snow cover affecting soil temperatures and runoff.

In short, the developing Super El Niño of 2026–27 is expected to tilt Iowa’s winter odds toward milder temperatures and lighter seasonal snow totals compared with a typical year. While cold and snow will still appear, the overall character of the season is likely to feel less severe than average for much of the state. Official seasonal outlooks from NOAA’s Climate Prediction Center will continue to refine these expectations as the event reaches its peak intensity later this year.