
Daily mean temperature anomalies around the world between 1st December and 20th December compared with the 30 year long term average between 1961 and 1990
The freezing conditions that have blasted Britain are being blamed on a series of weather patterns that are bringing Arctic temperatures to much of western Europe, California and even Australia.
One of the main factors is a change in the position of the jet stream - the fast-moving current of air that moves from west to east, high in the atmosphere.
Changes in the jet stream's path can cause massive changes in weather conditions across the globe and may be why Australians are now shivering their way through summer and the current freezing conditions in California.
In a normal British winter - when conditions are mild and soggy - the jet stream lies over northern Europe, at an altitude of between 35,000 to 50,000 feet.









