Will Ukraine Have a Warm Winter in 2026–2027?

Early seasonal models are leaning toward a mild European winter. Ukraine also currently has a warmer-than-normal base case, but that does not rule out snow, hard frosts or several sharp cold spells.

At the end of September, no one can reliably say what the weather in Kyiv, Lviv or Kharkiv will be on January 15. Ukraine’s Hydrometeorological Center stresses that detailed forecasts are designed for much shorter lead times; at seasonal range, the honest task is to estimate broad temperature and circulation tendencies rather than the weather on a specific date. Ukrhydrometcenter

The seasonal background is nevertheless becoming visible. The September update from the Copernicus Climate Change Service gives most of Europe a clear tilt toward above-average temperatures for December through February. That is not a guarantee for Ukraine, but it is strong enough to make the warm scenario the current base case. Copernicus

ORBK.NET’s current estimate: there is about a 65% chance that winter 2026/2027 in Ukraine will be clearly warmer than the 1991–2020 climate normal. A near-normal winter is assigned about 25%, and a colder-than-normal winter about 10%. Confidence: 62/100.

The most likely outcome is not “spring instead of winter.” It is a mild, changeable season in which longer thaws and above-freezing periods are interrupted by shorter episodes of real winter weather. A warm winter on average can still contain one or two memorable cold waves.

What counts as a warm winter?

A forecast needs a rule that can be checked later. We define winter as December 2026 through February 2027 and use Ukraine’s area-mean surface air temperature as the main indicator.

For this forecast, a warm winter means that the December–February mean is at least 0.5 °C above the 1991–2020 average. An anomaly from −0.5 to +0.5 °C is treated as near normal; below −0.5 °C is classified as colder than normal.

The climate baseline itself has shifted. According to the Ukrainian Hydrometeorological Institute, Ukraine’s average temperature in 1991–2020 was roughly 1.2 °C higher than in 1961–1990, with some of the strongest warming occurring in winter. This does not prove that 2026/27 will be warm, but it raises the starting probability compared with the climate of several decades ago. UHMI data

Why the models currently lean warm

The first reason is multi-model agreement. Seasonal forecasts are more useful when several major centers point in the same direction than when one individual model produces a dramatic signal. Copernicus C3S combines output from multiple international forecasting systems, and the September consensus favors above-average winter temperatures over much of Europe.

The second reason is the long-term warming trend. It does not determine any single season, but it adds a persistent background tilt toward warmer outcomes. A genuinely cold winter is still possible, but atmospheric circulation would have to overcome that background for a substantial part of the season.

A third factor is the strong 2026 El Niño. It affects global circulation, yet its impact on Ukraine is indirect. ERA5-based Copernicus analysis shows that European winters during El Niño can differ markedly because the North Atlantic, blocking patterns, the jet stream and the stratosphere can amplify or cancel the expected signal. El Niño is therefore a supporting factor, not a rule saying “El Niño means a warm Ukraine.” ERA5 analysis

The strongest case against the warm scenario

Ukraine’s winter depends heavily on where the air comes from and how long a circulation pattern persists. Active westerlies bring relatively mild Atlantic air into Europe. But persistent blocking over Greenland, Scandinavia or northern Europe can reorganize the flow and open a path for Arctic or continental cold.

The North Atlantic Oscillation, the polar vortex and possible sudden stratospheric warming events will matter. Their behavior cannot be forecast reliably for the whole winter in late September. That is why a 65% warm-season probability does not justify a claim that severe frost will not occur.

A winter could be mild through much of December, turn sharply cold for ten days in January, then return to repeated thaws. People may remember it as “cold,” while the three-month average still ends up clearly above normal.

Three scenarios for winter 2026/27

Does a warm winter mean little snow?

Not necessarily. Temperature and snow cover are related but not identical. A mild winter can still produce heavy snowfalls. The key question is how long the snow survives after it falls.

If temperatures repeatedly cross 0 °C, a common cycle may be snow → thaw → melt → refreeze → ice → new snow. Snow may fall several times while a persistent cover fails to survive for weeks across large parts of lowland Ukraine.

The same logic applies to frost. A season that averages 1–2 degrees above normal can still include several very cold days. That distinction matters for energy: the seasonal mean influences total heating demand, while a short cold wave determines peak stress.

When will the forecast become more reliable?

The most useful updates will come with new seasonal runs in October and November. By early November, we should know more about the North Atlantic background, El Niño and the early structure of the polar vortex.

Another key point is late November and early December, when sub-seasonal guidance starts to add useful information about the opening of winter. Even then, however, a forecast for a particular day in February will remain beyond reliable range.

What would change the probability?

The 65% estimate would rise if October and November multi-model forecasts continue to show a persistent warm anomaly over Eastern Europe and the Atlantic remains active without durable northern blocking. In that case the probability could move into the 70–80% range.

It would fall if successive model updates begin to favor a colder Eastern European circulation regime, especially one involving durable blocking that repeatedly delivers cold air into Ukraine. One early snowfall or one cold week is not enough: a meaningful update requires a structural signal across several consecutive forecasts.

So, will winter 2026/2027 be warm or cold?

As of September 24, 2026, the best-supported answer is: winter 2026/2027 in Ukraine is more likely than not to be warmer than the 1991–2020 climate normal.

That does not mean “no snow” or “no frost.” The most realistic picture is a variable winter dominated by milder spells and frequent crossings of the freezing point, interrupted by shorter periods of genuine cold. The September signal is strong enough to rank the warm scenario first, but not strong enough to treat the outcome as settled.

Forecast card

This forecast was prepared using the ORACLE Foresight Engine methodology. The initial 65% estimate is an immutable snapshot; later changes should be published as separate dated updates.

Forecast disclaimer. This forecast does not state that the event will happen. It represents a current probability assessment based on information available at the time of publication and may change as new information appears.