Why Is It So Cold? Global Weather Patterns Explained

Heavy snowfall in Livorno, Tuscany

If the planet is warming, why are we still getting extreme cold weather? It is a fair question and one that speaks to how complex weather systems interact with our changing climate. While average global temperatures are rising, local cold spells are still very possible. The science behind this lies in global air circulation, jet streams and Arctic dynamics.

Cold Spells in a Warming Climate

Global warming does not mean every place gets warmer all the time. Instead, it means the overall average temperature of the Earth is rising. Within that trend, there will still be cold days and even harsh winters. In fact, climate disruption is making weather systems more unpredictable.

Read more in What’s the Difference Between Weather and Climate?

Polar Vortex and Arctic Air Explained

The polar vortex is a large area of low pressure and cold air that sits over the Arctic. It exists year-round but strengthens in winter. When the polar vortex is stable, it keeps cold air locked near the poles. But when it weakens, that air can spill southwards into North America, Europe or Asia.

This weakening often follows sudden warming in the stratosphere, which disrupts the polar vortex. The result is Arctic air reaching areas that do not usually experience such extreme cold.

Jet Stream Wobbles and Blocking Patterns

The jet stream is a fast-moving river of air high above the Earth. It forms where cold polar air meets warmer tropical air. As the Arctic warms, this temperature difference shrinks, weakening the jet stream.

A weaker jet stream can become wavy or stuck, creating “blocking” patterns. These allow cold air to settle over one area for a longer period.

Explore this more in Why the Jet Stream Is Key to Britain’s Weather Swings.

Global Examples of Extreme Cold Weather

These weather dynamics have led to several notable cold snaps around the world:

• In 2021, much of Texas and the southern United States experienced historic snowfall and power outages
• Northern India and Pakistan have seen unseasonal frost and record-low temperatures in recent years
• Japan and South Korea regularly experience cold air outbreaks from Siberia
• Central Europe has seen heavy snowstorms following polar air intrusions

These events are all part of the same global system. They do not contradict climate change; they help us understand it better.

Why Climate Change Can Cause More Global Extremes

A warming planet means more energy and moisture in the atmosphere. This can amplify all types of weather; not just heatwaves but also cold spells, storms and rainfall.

Climate change does not move in straight lines. It creates disruption, shifting long-standing weather patterns and making extremes more likely. Cold weather, especially when it lasts longer than expected, is part of this larger disruption.

Explore further in Extreme Climatic Conditions: What They Are and How They Affect the UK.

How to Stay Safe During a Cold Snap

Sudden cold spells can be dangerous. Whether you are in a rural village or a busy city, preparation makes a difference:

• Dress in layers and protect extremities
• Keep heating systems serviced and consider better insulation
• Avoid unnecessary travel during severe weather
• Check in on vulnerable neighbours and use the strength of community

Want to Know Why the UK Is So Cold Right Now?

Looking for a more specific breakdown of British cold weather? Read our UK-focused explainer: Why Is It So Cold in the UK? Weather Patterns Behind Britain’s Cold Spells.

Global Weather Pattern FAQs

Why is it cold if the climate is warming?
Climate change is about long-term averages. Cold spells can still happen, especially when Arctic air moves into warmer regions.

What causes cold snaps around the world?
Cold snaps are often caused by disruptions to the polar vortex or jet stream. These allow cold air to move into areas that are usually milder.

What is the polar vortex and how does it work?
It is a large circulation of cold air around the Arctic. When stable, it keeps cold air contained. When disrupted, it releases that air into lower latitudes.

Does cold weather disprove global warming?
No. It highlights how climate change makes weather patterns more unstable and extreme, including both heat and cold.

Sources:

• https://weather.metoffice.gov.uk/learn-about/weather/atmosphere/global-circulation-patterns
• https://www.noaa.gov/education/resource-collections/weather-atmosphere/weather-systems-patterns

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