Europe gets hit with bitter cold spells because of a combination of forces: massive high-pressure systems pushing freezing air westward from Siberia, a jet stream that occasionally buckles and lets Arctic air flood southward, and the sheer size of the Eurasian landmass cooling rapidly in winter. What makes these cold snaps feel surprising is that Europe is normally much warmer than you’d expect for its latitude, thanks to Atlantic Ocean currents and prevailing westerly winds. When those warming mechanisms falter, temperatures can plunge fast.
Europe Is Actually Warmer Than It Should Be
Before understanding why Europe gets cold, it helps to know that most of the time, Europe is unusually warm for how far north it sits. London and Calgary, Canada, are at nearly the same latitude, but their winters couldn’t be more different. In January, London’s average high is 47°F while Calgary’s is 31°F. The overnight lows are even more dramatic: London stays around 39°F while Calgary drops to 13°F. That 26-degree gap in nighttime temperatures exists purely because of how Atlantic warmth reaches the British Isles.
Warm ocean water carried northward by the Atlantic current system releases heat into the atmosphere, and prevailing westerly winds push that mild, moist air across Western Europe. This is why coastal cities like London, Dublin, and Lisbon enjoy relatively gentle winters despite sitting as far north as parts of Canada where temperatures regularly hit well below zero. The further east you travel from the Atlantic coast, the weaker this warming effect becomes. Moscow, Warsaw, and Helsinki all experience much harsher winters than cities at the same latitude along the coast.
The Siberian High Pushes Freezing Air West
The single biggest driver of Europe’s coldest winter episodes is a massive dome of high pressure that builds over Siberia each autumn. As Asia’s enormous landmass cools, dense, frigid air settles over the region and strengthens into what meteorologists call the Siberian High, one of the most powerful pressure systems on the planet. Snow cover plays a direct role in how strong it gets: when Siberian snow cover is unusually high, air temperatures drop further, and the high-pressure system intensifies.
Once this cold air mass is established, it doesn’t just sit still. The pressure difference between Siberia and areas to the west causes the cold air to spread outward, propagating toward western Russia and northern Europe. When the atmospheric setup is right, this easterly flow overrides the normal pattern of mild Atlantic air reaching the continent, replacing it with air that originated thousands of miles away over frozen ground. These are the events that bring sub-zero temperatures to places like Paris, Berlin, and even parts of Spain, catching residents off guard because their climate is normally so mild.
When the Jet Stream Buckles
The polar jet stream is a ribbon of fast-moving air high in the atmosphere that normally acts as a boundary between cold Arctic air to the north and warmer air to the south. When it flows in a relatively straight path across the Atlantic and into Europe, the continent stays mild. The problems start when the jet stream develops large, slow-moving waves.
These waves can create what are called blocking patterns, where high-pressure systems stall in place and redirect the jet stream into dramatic loops. When a blocking high parks itself over Scandinavia or the North Atlantic, it acts like a dam. Instead of mild westerly winds reaching Europe, the flow reverses, pulling frigid continental or Arctic air southward and westward across the continent. These blocking events can persist for 11 days or more, and their persistence has been increasing by roughly 2 days per decade in recent years. The longer a block holds, the more extreme the temperature departure from normal.
Polar Vortex Disruptions and Cold Outbreaks
High above the jet stream, the polar vortex is a large circulation of cold air spinning over the Arctic during winter. When it’s strong and stable, cold air stays bottled up near the pole. When it weakens, shifts, or splits apart, the jet stream below it becomes extremely wavy, allowing warm air to flood into the Arctic while polar air sinks deep into the mid-latitudes.
These disruptions often start with events called sudden stratospheric warmings, where the upper atmosphere above the Arctic heats up dramatically over just a few days. This happens roughly six times per decade. During the winter of 2023/2024, two major events occurred in a single season, something that only happens about once per decade on average. Not every stratospheric warming translates into cold weather at ground level. The January 2024 event was short-lived and had little surface impact, while the March event followed a more typical pattern of weakening the vortex, though its coupling to surface weather was still relatively mild.
Research from NOAA has linked regional variations in Arctic sea ice to where the polar vortex positions itself. Lower-than-average sea ice in the Barents and Kara Seas (the waters north of Scandinavia and Russia) has been connected to a shift of the polar vortex toward Eurasia, bringing colder-than-average winters to Siberia and central Eurasia. Climate models that incorporate realistic sea ice loss tend to predict a weaker polar vortex overall, which could mean more frequent cold air outbreaks into Europe even as the planet warms on average.
The Atlantic Current Is Slowing Down
The same ocean circulation that keeps Europe warmer than its latitude suggests may be losing strength. The Atlantic Meridional Overturning Circulation, the large-scale system of currents that carries warm tropical water northward, remained stable from 1955 to 1994 but has declined in both strength and speed over the last two decades, according to data from NOAA’s National Centers for Environmental Information.
A weaker circulation means less warm water reaching the North Atlantic, which means less heat released into the air that westerly winds carry across Europe. The projected effect is straightforward: tropical regions retain more warmth while higher latitudes receive less of it, making hot areas hotter and cold areas colder. This doesn’t mean Europe will suddenly freeze, but it does mean the ocean-driven warming that has kept European winters so mild compared to Canada or northern Asia could gradually diminish, making the continent more vulnerable to cold extremes.
Why Western and Eastern Europe Feel So Different
The temperature difference between Europe’s Atlantic coast and its continental interior during winter is striking. Western Europe sits in a temperate maritime climate zone, where the ocean moderates both summer heat and winter cold. Winters are cool and damp but rarely severe. Eastern Europe and Russia fall into a continental climate zone, where the ocean’s influence is minimal and temperature swings between seasons are far larger.
This gradient explains why a cold event that brings temperatures to minus 10°C in Moscow might only push London down to 0°C during the same episode. The Atlantic acts as a thermal buffer that weakens with distance. Cities like Warsaw, Prague, and Budapest sit in a transitional zone where they get some ocean influence in a normal winter but are fully exposed when easterly winds bring Siberian air. This is why Central Europe often bears the brunt of the continent’s worst cold snaps: close enough to the cold source, far enough from the ocean’s warmth.