T-shirts instead of winter coats: what a warm October reveals about winter
At the start of October, temperatures of up to 25C give parts of Europe a last taste of late summer. Yet, according to an old farmers' rule, a warm autumn can herald a severe winter. What do the statistics and meteorologists say?
People out and about these days often still do not need a jacket. October is starting with unusually mild temperatures, with around 25 degrees possible in some countries. After the wet, changeable weather many associate with autumn, it almost feels like a belated summer week.
Yet, according to an old farmers' saying, this fine weather is precisely what should give cause for concern: "If October is warm and fair, a harsh winter will follow."
If you take the saying at face value, you should already be digging out scarf, gloves and snow shovel. The friendlier October is meant to be, the harder the winter that follows. But is that really true?
Is a warm October a warning sign?
Farmers' rules once served as a kind of weather calendar. Long before satellites, weather balloons and computer models were available, people spent generations observing how the seasons unfolded. The experience they gained produced rhymes that were easy to remember and meant to provide guidance for farming and everyday life.
The snag is that something which seems plausible over decades is still far from being a reliable link. That is why, when it comes to October and the winter that follows, it is worth looking back – and history provides a fairly spectacular counter-example.
When the farmers' rule missed the mark completely
Autumn 2006 in Germany, for example, was exceptionally warm. Anyone relying on the old rule back then would have braced for a bitterly cold winter.
It turned out exactly the other way round: the winter of 2006/07 became the warmest in Germany since regular weather records began in 1901. The German Weather Service (DWD) calculated at the time (source in German) an average temperature of 4.3 degrees Celsius – 4.1 degrees above the long-term mean. There was no prolonged spell of frost.
December 2006 was also exceptionally mild, and January set a new temperature record. The old rule had produced about the worst forecast imaginable.
Why October does not 'pre-programme' January
Measurement data show that the current impression of a 'summer-like autumn' is not just subjective. According to the German Weather Service, September 2026 in Germany averaged 15.9 degrees, 2.6 degrees above the long-term norm. Rainfall was also significantly below usual levels.
On 30 September, 31 degrees were recorded on the Upper Rhine and 29 degrees in northern Baden. On 1 October temperatures reached 25 degrees in Bavaria and Saxony and 23 to 25 degrees in Berlin and Brandenburg. That does not mean, however, that the whole of October will continue like this. The weather pattern is expected to shift in the coming days, with temperatures falling.
The weather in Germany is shaped by large-scale airflows. In the winter months, factors such as pressure patterns over the Atlantic, the so-called North Atlantic Oscillation and changes in the Arctic atmosphere play a role. The polar vortex can also influence how cold air masses are distributed.
That is why specific weather forecasts over several months are difficult even with modern models. The further ahead you look, the less it is about pinpointing the weather on a particular day and the more it is about probabilities and possible developments.
El Niño and its influence
One factor still makes the outlook for winter 2026/27 interesting: El Niño.
The climate phenomenon in the tropical Pacific is currently developing with unusual strength. According to the US National Oceanic and Atmospheric Administration (NOAA), there is more than a 90 per cent probability of a very strong El Niño event in autumn and winter 2026/27.
For October to December, NOAA puts the chance at 75 per cent that the intensity of the phenomenon will exceed all previous El Niño events since 1950.
El Niño influences the global climate system, but its effects vary widely from region to region and depend on other atmospheric conditions. NOAA itself stresses that any impacts are not guaranteed.
So will there be snow after all?
A cold winter is of course not ruled out. Even after a very mild autumn, wintry conditions can still set in during January or February.
But as a piece of weather lore from a time before satellites, the old farmers' rule offers no robust forecast. So anyone who sees an ice-cold winter looming just because temperatures reach 20 or 25 degrees at the start of October can afford to relax. A warm October is not a meteorological countdown to frost.
