EUMETSAT Study Ties El Niño Summers to Warmer, Sunnier, Drier Europe

EUMETSAT has published a case study concluding that European summers tend to run warmer, sunnier and drier during El Niño, and that the very strong event under way in 2026 may have partly amplified the heat and dryness recorded across much of the continent this year. The analysis, announced on 6 October 2026, draws on more than three decades of satellite observations together with other long-term records.

What the satellite record shows

According to EUMETSAT, the study examined data spanning at least six El Niño and six La Niña events since 1991. It found that El Niño summers were, on average, warmer, sunnier and drier than normal over much of Europe, while La Niña summers tended to be cooler, cloudier and wetter. EUMETSAT states that across a broad area of Europe the gap between the two composites is too large to be explained by natural variation alone. The authors report that the heat and drought observed in Western and Central Europe during summer 2026 were broadly consistent with that pattern.

"El Niño and its cold counterpart, La Niña, both influence winds and rainfall across the tropics in different ways, increasing the risk of drought in some regions and flooding in others," said Rob Roebeling, Climate Product Expert at EUMETSAT and an author of the case study. He described the two as opposite phases of the El Niño–Southern Oscillation, which he called the biggest single source of year-to-year variation in the global climate, adding that tropical effects are well documented while the influence at higher latitudes, including Europe, "is often less clear."

On the physical pathway, Roebeling said the findings fit the idea that by changing large-scale patterns of rising and sinking air over the tropics, El Niño can trigger large meanders in the jet streams — the mechanism known as atmospheric teleconnections.

The summer of 2026 in context

EUMETSAT cites figures from the Copernicus Climate Change Service (C3S), implemented by the European Centre for Medium-Range Weather Forecasts on behalf of the European Commission. C3S reported that summer 2026 was Europe's third warmest on record and western Europe's warmest, at 2.5°C above the 1991-2020 average. A record 52% of the continent experienced at least "very strong" heat stress, and near-record sea-surface temperatures were observed across European seas.

EUMETSAT is explicit that ENSO is not the principal cause. The case study's authors note that El Niño effects come on top of long-term warming from human-induced climate change, which they describe as the main driver of Europe's recent record-breaking summers regardless of the phase of ENSO. EUMETSAT points out that the continent's five warmest summers on record have all occurred since 2021.

The agency also references the state of the current event: in early September 2026 the World Meteorological Organization confirmed that El Niño was firmly established and forecast it to become a very strong event, almost certain to last through February 2027, with effects persisting considerably longer into the year.

What it implies for the months ahead — with caveats

Roebeling set out the historical seasonal sequence while stressing its limits. "In El Niño events of the past 35 years, European winters were on average milder and wetter than normal, followed by warmer and cloudier springs," he said. "But other factors, such as blocking weather systems or unusually warm seas, can strengthen or reduce El Niño's influence, so how this winter and next year will turn out remains uncertain."

The study is built on soil moisture and solar radiation climate normal and anomaly products from EUMETSAT's Satellite Application Facilities. EUMETSAT says these recently introduced products follow World Meteorological Organization standards and reference periods and are distributed through its Climate Anomalies and Normals service, which also carries a range of other normal and anomaly products. The full case study is available on the EUMETSAT User Portal.

Readers can find background on the mechanisms involved in the science section and on how indices are constructed in the glossary.