Holiday warmth across the U.K.

This year, Christmas is expected to be exceptionally mild in the United Kingdom and Ireland. Climate Central analysis shows that the unusually warm late-December temperatures forecast for the holiday (December 24-25) are at least twice as likely to occur due to human-caused climate change. 

Note: Use the Climate Shift Index map to stay updated on heat in your region.

How unusual is this forecasted holiday warmth?

• During these two days, daily high temperatures across the UK and Ireland are forecast to range between 3°C and 6°C above the 1991-2020 climate normals. In Scotland, high temperatures are expected to be even warmer, running as much as 8°C to 9°C above the late-December average. 

• Low temperatures are forecast to range between 5°C and 10°C, or up to 10°C above the historical average, described as “surprisingly high” by the Met Office.

• Exceptionally mild maximum temperatures could reach as high as 12°C and 14°C on both Christmas Eve and Christmas Day. 

• An atmospheric high pressure system located to the south of the UK will contribute to the unusually mild Christmas holiday.

How has climate change influenced this winter warmth?

• Daily average temperatures are expected to reach Climate Shift Index (CSI) levels of 5 in the UK and Ireland. A CSI level 5 indicates that human-caused climate change made this unusual warmth at least 5 times more likely, signifying an exceptional climate change event. 

• Over the two-day period nearly 682,000 people in the UK and Ireland will experience at least one day with CSI level 5.

• More than 41 million people will experience at least one day with CSI level 3.

What do experts say?

Dr. Kristina Dahl, VP for Science at Climate Central, said: 

“The unusually warm temperatures in the UK and Ireland over the Christmas holiday bear the clear fingerprints of climate change and are the latest indication that winters in the region are warming. The UK is already experiencing an additional 11 days per year above freezing due to climate change, and we expect that trend to continue as long as we continue burning fossil fuels like coal, oil, and gas.” 

How do we know climate change is influencing this warmth?

The Climate Shift Index uses peer-reviewed methodology and real-time data to estimate how climate change has increased the likelihood of a particular daily temperature.

We compare the likelihood that these temperatures would occur in a world without carbon emissions released by humans, versus in today’s world with decades of carbon emissions building up in the atmosphere. This is an established scientific method to determine how much climate change has or has not affected individual extreme weather events.

Reporting resources

Until carbon emissions are reduced, temperatures during the winter season will continue to become milder across the globe. Explore quick facts and local analyses on the links between climate change and warming wintertime temperatures in: Climate Central’s Lost Winter: Above-freezing days added by climate change 

Major funding provided by the Bezos Earth Fund.