Why Western Europe Has Milder Winters Than North America at the Same Latitude

Why Western Europe is Warmer in Winter

Many people expect places at the same latitude to have similar climates, but parts of Western Europe enjoy much milder winters than North American locations on the same parallel. London (51.5°N) has an average January high near 47°F (8.3°C), while Calgary (~51°N) averages highs in the low 30s°F (≈0°C). Similar contrasts appear between Madrid and New York, or Vienna and Grand Forks, North Dakota.

Main reasons

1. Heat transported by Atlantic currents (AMOC)
A major factor is the Atlantic Meridional Overturning Circulation (AMOC), a system of ocean currents that moves warm tropical water northward. The AMOC — including the Gulf Stream — transports enormous amounts of heat into the North Atlantic. That heat warms the air above the ocean and helps keep Western Europe comparatively mild in winter.

2. Prevailing westerly winds
Prevailing westerlies blow from the Atlantic toward Europe, carrying maritime air inland. In winter these winds strengthen, so the ocean’s relatively warm air spreads across Europe like a “fan-assisted heater,” moderating coastal and nearby inland temperatures.

3. Europe’s geography and continentality
Europe is a relatively narrow east–west landmass bordered by ocean on the west. Water stores heat more effectively than land: it warms in summer and releases that heat in winter. By contrast, many North American winter-cold regions lie deep within a large continental landmass (greater continentality), where temperatures swing more extremely between seasons.

4. Atmospheric circulation patterns over North America
The jet stream and atmospheric waves related to the Gulf Stream can bring cold polar air deep into North America. The jet stream often dips southward downstream of the Rocky Mountains, allowing Arctic air masses to spill into the United States and Canada. A 2011 Nature study estimated that atmospheric responses to the Gulf Stream can account for a sizable portion of cross‑ocean temperature differences.

What about the U.S. East Coast?

The Gulf Stream carries warm water north along the U.S. East Coast, but the combination of atmospheric circulation patterns, large continental interior, and the orientation of prevailing winds means the heating effect that benefits Europe is not delivered in the same way to interior North America or even some coastal U.S. locations. Local geography and the behavior of the jet stream are decisive.

Climate change and the AMOC

Scientists warn that climate change may weaken the AMOC. A 2023 paper co-authored by Peter Ditlevsen suggested the AMOC could collapse between now and 2095 under some scenarios, earlier than previously thought. If a major slowdown or collapse occurred, Northern Europe could cool substantially and experience shifts in precipitation and growing seasons — with potentially serious consequences for agriculture and ecosystems. However, there is uncertainty in timing and magnitude; researchers emphasize that projections depend strongly on future greenhouse gas emissions.

Bottom line: Warm Atlantic currents, winter westerlies, and Europe’s maritime geography combine to give Western Europe milder winters than many North American locations at the same latitude. That advantage could change if major ocean circulation patterns are disrupted by climate change.

Notes: Temperatures cited are average January highs referenced in the original reporting (January 2024 values for some regions). Sources discussed include experts from the National Oceanography Centre and University College London, and peer-reviewed studies on ocean–atmosphere interactions and the AMOC.