Winter 2026-2027 in Europe: what a record-strength El Niño means for snow and cold

The World Meteorological Organization (WMO) said on 8 October 2026 that the Niño 3.4 sea-surface temperature anomaly — the standard index used to measure El Niño strength — is forecast to reach approximately +3.7°C during October-November-December 2026, with warming peaking around December. The WMO update describes the spread among forecast models as narrow, meaning confidence in the figure is high.

The WMO's October update does not itself offer a historical comparison for this figure. Other forecasters frame the event's exceptional nature differently: Severe Weather Europe's October analysis describes it as the strongest El Niño in over 75 years, while climatologist Massimiliano Fazzini, speaking to the Italian news agency ANSA, called it the strongest in roughly 140 years. The two assessments do not agree on an exact historical ranking, but both describe the current event as unusually intense.

How El Niño changes Europe's winter

El Niño is a periodic warming of surface waters in the central and eastern tropical Pacific. It does not affect Europe as directly as it affects the Pacific basin, but it alters global atmospheric circulation enough to shift the jet stream and storm tracks reaching the continent, meteorologist Andrej Flis explained in a winter outlook published on Severe Weather Europe on 7 October 2026 and updated on 15 October.

According to Flis's analysis, a persistent mild westerly flow from the Atlantic is expected to dominate the season, pushing average temperatures above normal across most of Europe. Low-pressure systems are forecast to track from the Atlantic into northern Europe, occasionally dragging colder northerly air behind them, which could bring short, sharp cold intrusions rather than a sustained freeze.

Less snow at low and mid elevations

The same outlook projects below-average natural snowpack across most of western, central and southern Europe for the coming winter. The clearest snow potential is confined to northern regions and Alpine elevations above roughly 1,800-2,000 metres, where temperatures should stay cold enough for accumulation even as Atlantic systems bring abundant moisture lower down as rain.

A separate report citing Flis's modelling, published by Libero on 14 October 2026, said December 2026 and January 2027 are both expected to bring below-average snow quantities in the Alps, with February 2027 flagged as the potentially most snow-poor month for the continent. The same report stressed that the projections are still provisional at this range and based partly on data from the European Centre for Medium-Range Weather Forecasts (ECMWF).

A climatologist warns of an "extreme" winter

Not every forecaster frames the season as simply mild. Massimiliano Fazzini, head of the Climate Risk Team at the Italian Society of Environmental Geology and a professor at the University of Camerino, told ANSA on 14 October 2026 that the winter is likely to be unusually variable, with "rapid alternation of warm periods above average, very humid, with sudden cold waves." He added that these cold waves are expected to arrive from more northern latitudes.

Fazzini linked this volatility to the exceptional strength of the current El Niño — which he called the strongest in roughly 140 years — noting that its effects on European and Mediterranean weather typically arrive through teleconnections six to eight months after the event begins, which would place the strongest impacts in the heart of the European winter.

What forecasters agree on — and what remains uncertain

Across the sources, two points are consistent: the El Niño event itself is forecast to be historically strong, and European winter temperatures are more likely than not to run above the long-term average. The WMO's broader seasonal guidance also points to wetter-than-normal conditions for much of central and western Europe this winter, without ruling out cold spells.

Where sources diverge is on how smooth or turbulent that mild winter will feel. Flis's snowfall modelling points to a generally quiet, low-snow season outside high mountains, while Fazzini's framing emphasises abrupt swings between warm, humid spells and sudden cold outbreaks. All sources caution that seasonal forecasts at this range describe broad tendencies over months, not day-to-day weather, and that short-term cold spells or heavy local snowfall cannot be excluded even in a milder overall winter.

Why this matters now

Interest in the forecast is high because an unusually strong El Niño raises the stakes for sectors from ski tourism to energy demand and agriculture, and because the signal is strong enough this early in autumn that major agencies, including the WMO, are issuing confident numerical forecasts months before the winter itself. The WMO update notes the near-record ocean warmth is expected to persist through the winter months, keeping El Niño's global influence active into early 2027.