As October opens, many Europeans are reaching for T-shirts rather than winter coats. In Germany, temperatures hit 25°C in Bavaria and Saxony on 1 October, with similar readings in Berlin and Brandenburg. The Upper Rhine saw 31°C on 30 September. It feels less like autumn and more like a late summer encore.
This balmy spell has revived an old piece of weather lore: “If October is warm and fair, a harsh winter will follow.” Taken at face value, it would have you digging out scarves and snow shovels already. But does a friendly October really pre-programme a freezing winter?
Farmers' rules: folklore or forecast?
Farmers' sayings were once practical guides, distilled from generations of observing seasonal patterns before satellites and computer models existed. They offered memorable rhymes to help plan sowing and harvesting. Yet what seems plausible over decades is far from a reliable scientific link.
History provides a striking counter-example. In 2006, Germany experienced an exceptionally warm autumn. Anyone trusting the old rule would have braced for a brutal winter. Instead, the winter of 2006/07 became the warmest since records began in 1901, with an average temperature of 4.3°C—4.1°C above the long-term mean. December was exceptionally mild, and January set new records. The farmers' rule had produced about the worst forecast imaginable.
Why October doesn't dictate January
Current data confirm that this warm start is not just a subjective impression. The German Weather Service (DWD) reported that September 2026 averaged 15.9°C, 2.6°C above the norm, with rainfall well below usual levels. But such anomalies do not lock in the rest of the season. Weather patterns are expected to shift in the coming days, bringing cooler temperatures.
Winter weather in Europe is shaped by large-scale airflows, including pressure patterns over the Atlantic, the North Atlantic Oscillation, and changes in the Arctic atmosphere. The polar vortex can also influence how cold air masses spread. These complex interactions make long-range forecasts difficult even with modern models. The further ahead you look, the more it becomes about probabilities rather than precise predictions.
El Niño adds a wildcard
One factor makes the winter 2026/27 outlook particularly interesting: El Niño. The climate phenomenon in the tropical Pacific is developing with unusual strength. According to the US National Oceanic and Atmospheric Administration (NOAA), there is more than a 90% probability of a very strong El Niño event during autumn and winter. For October to December, NOAA puts the chance at 75% that its intensity will exceed all previous events since 1950.
El Niño influences the global climate system, but its effects vary widely by region and depend on other atmospheric conditions. NOAA itself stresses that impacts are not guaranteed. For Europe, El Niño can sometimes bring milder winters, but it is not a simple switch.
This uncertainty comes as Europe faces other winter challenges. Thin gas reserves and high prices have already prompted warnings from EU energy officials. Meanwhile, Kyiv's winter sky remains under threat from Russian strikes, as the war continues to strain energy infrastructure. A mild winter would ease some pressure, but a cold snap could test preparedness.
So, will there be snow?
A cold winter is not ruled out. Even after a very mild autumn, January or February can still bring wintry conditions. But the old farmers' rule offers no robust forecast. It is a relic from a time before weather science.
So if you see temperatures of 20 or 25°C at the start of October and worry about an ice-cold winter, you can relax. A warm October is not a meteorological countdown to frost. The real drivers of winter weather are far more complex, and even the best models can only offer probabilities, not certainties.
