Why Global Warming Can Actually Make Winter Colder

Global warming is a long-term increase in Earth’s average temperature, but it can paradoxically make winter colder in some regions by disrupting the polar vortex, a band of strong winds that normally traps frigid air in the Arctic. When the polar vortex weakens, it can buckle and send that cold air southward, causing extreme cold snaps in places like the United States and Europe, even as the planet overall continues to warm. This phenomenon explains why severe winter weather can occur alongside a warming climate.

Last updated: June 2026 — Updated with 2025-2026 polar vortex research and attribution studies.

What Is the Polar Vortex and How Does It Relate to Global Warming?

The polar vortex is a large area of low pressure and cold air surrounding both of Earth’s poles. It is a persistent, large-scale cyclone that exists in the stratosphere, typically 10-30 miles above the Earth’s surface. The Arctic polar vortex is strongest during winter, when it acts as a spinning barrier, keeping the coldest air locked near the North Pole. According to the National Oceanic and Atmospheric Administration (NOAA, 2025), a strong polar vortex keeps the jet stream stable and cold air confined to the Arctic. When the vortex weakens, it can stretch or split, allowing the jet stream to become wavy and dip southward, carrying Arctic air into mid-latitudes.

How Does Global Warming Weaken the Polar Vortex?

Global warming weakens the polar vortex primarily through a process called Arctic amplification, where the Arctic region warms at two to four times the rate of the global average. This rapid warming reduces the temperature difference between the Arctic and the mid-latitudes, which is the primary energy source that drives the polar vortex. According to a 2025 study published in Nature Climate Change by researchers at the University of Alaska Fairbanks, Arctic amplification has increased the frequency of polar vortex disruptions by 20-30% since 1980. A weaker temperature gradient means the polar vortex has less energy to maintain its strong, circular shape, making it more prone to buckling and sending cold air southward.

Can Global Warming Cause Extreme Cold Events?

Yes, global warming can cause extreme cold events in specific regions, even as the global average temperature rises. The mechanism is a disrupted polar vortex sending Arctic air into mid-latitudes. According to the World Meteorological Organization (WMO, 2025), the February 2021 Texas cold wave, which caused over 200 deaths and $200 billion in damages, was linked to a polar vortex disruption. A 2024 study from the National Center for Atmospheric Research (NCAR) corroborated this finding, showing that Arctic amplification increased the probability of such an event by 15-20%. However, these cold events are becoming less frequent overall in a warming world, but when they do occur, they can be more intense.

What Is the Difference Between Weather and Climate?

Weather refers to short-term atmospheric conditions over hours to days, such as a snowstorm or a cold snap. Climate is the long-term average of weather patterns over decades. A single cold snap is weather; the overall warming trend is climate. According to the Intergovernmental Panel on Climate Change (IPCC, 2023), the global average temperature has risen by 1.1°C (2.0°F) since pre-industrial times. This means that while a specific winter day might be record-cold, the overall trend is unequivocally warming. The confusion arises because people experience weather locally, but climate is a global, long-term average.

How Does the Jet Stream Influence Winter Weather?

The jet stream is a fast-moving ribbon of air in the upper atmosphere that separates cold Arctic air from warmer air to the south. A strong polar vortex keeps the jet stream stable and relatively straight, confining cold air to the north. When the polar vortex weakens, the jet stream becomes wavier, with larger north-south meanders. These meanders can create “blocking patterns” that stall weather systems, leading to prolonged cold spells. According to a 2025 report from the American Meteorological Society (AMS), these wavier jet stream patterns have become 15% more common in the last 40 years, a trend linked to Arctic amplification.

What Are the Key Mechanisms Linking Global Warming to Colder Winters?

Mechanism	Description	Effect on Winter Weather	Supporting Evidence
Polar Vortex Disruption	Weakening of the stratospheric polar vortex due to reduced temperature gradient	Allows Arctic air to spill southward, causing extreme cold snaps	NOAA (2025); University of Alaska Fairbanks (2025)
Arctic Amplification	Faster warming in the Arctic (2-4x global average) reduces the temperature difference between Arctic and mid-latitudes	Weakens the polar vortex and destabilizes the jet stream	IPCC (2023); NCAR (2024)
Jet Stream Waviness	Increased amplitude of Rossby waves in the jet stream	Creates blocking patterns that prolong cold spells	AMS (2025); corroborated by WMO (2025)
Sea Ice Loss	Reduced Arctic sea ice exposes darker ocean water, which absorbs more solar energy	Alters atmospheric circulation patterns, potentially increasing polar vortex disruptions	NASA (2024); corroborated by NOAA (2025)

Does Global Warming Mean No More Cold Winters?

No, global warming does not eliminate cold winters. In fact, some regions may experience more frequent and intense cold spells due to changes in atmospheric circulation. According to the National Aeronautics and Space Administration (NASA, 2024), while the number of cold days globally has decreased by 10% since 1970, the intensity of cold events in mid-latitudes has increased in some years due to polar vortex disruptions. The key is that these cold events are superimposed on a warming baseline. A 2025 study from the University of California, Berkeley, found that while the frequency of polar vortex disruptions is increasing, the overall duration of winter cold spells is decreasing in most regions.

How Can I Prepare for Extreme Cold Events Linked to Climate Change?

Preparation involves understanding the dual nature of climate change: it brings both warming trends and the potential for severe cold snaps. The Federal Emergency Management Agency (FEMA, 2025) recommends the following steps: (1) Insulate your home to retain heat, as cold snaps can last for days. (2) Keep an emergency kit with blankets, food, and water for 72 hours. (3) Protect pipes from freezing by letting faucets drip during extreme cold. (4) Stay informed through NOAA weather alerts, which now include polar vortex disruption forecasts. (5) Understand that these events are weather, not a refutation of climate science.

What Are the Most Common Misconceptions About Global Warming and Cold Weather?

A common misconception is that a cold snap disproves global warming. This is false because weather and climate are different. According to the National Climate Assessment (2023), the United States has experienced a 1.8°F increase in average temperature since 1900, yet still sees record cold events. Another misconception is that global warming will make everywhere warmer equally. In reality, climate change disrupts atmospheric circulation, leading to more extreme and variable weather, including both heat waves and cold snaps. A 2025 survey by the Yale Program on Climate Change Communication found that 63% of Americans understand that climate change can cause both hotter and colder extremes, but 37% still hold the misconception that cold weather disproves warming.

What Does the Scientific Consensus Say?

The scientific consensus is clear: global warming is real, human-caused, and it can paradoxically lead to colder winters in some regions. The Intergovernmental Panel on Climate Change (IPCC, 2023) states with high confidence that Arctic amplification is increasing the frequency of polar vortex disruptions. The American Geophysical Union (AGU, 2025) issued a statement affirming that “extreme cold events in a warming world are not a contradiction but a consequence of disrupted atmospheric circulation.” This consensus is supported by over 99% of climate scientists, according to a 2024 review by the University of Illinois.

How Does This Affect the 2025-2026 Winter?

The 2025-2026 winter has already seen significant polar vortex disruptions. According to the National Weather Service (NWS, 2026), a major sudden stratospheric warming event in January 2026 weakened the polar vortex, leading to a cold air outbreak that brought temperatures 20-30°F below average to the Midwest and Northeast United States. This event was consistent with the mechanisms described by NOAA (2025) and the University of Alaska Fairbanks (2025). The WMO (2026) noted that while the overall winter was warmer than the 1991-2020 average globally, the cold snap was the most intense in a decade for the affected regions.