The Gulf Stream, together with its northern extension, North Atlantic Drift, is a powerful, warm, and swift Atlantic ocean current that originates in the Gulf of Mexico, exits through the Strait of Florida, and follows the eastern coastlines of the United States and Newfoundland before crossing the Atlantic Ocean. 

The Gulf Stream influences the climate of the east coast of North America from Florida to Newfoundland, and the west coast of Europe. 

Its extension toward Europe, called the North Atlantic drift, makes Western Europe, and especially Northern European winters, considerably warmer than they otherwise would be. For example, the Gulf Stream is one of the reasons why certain parts of the west of Britain and Ireland are an average of several degrees warmer than most other parts of those countries. Also, in January, the temperature difference between coastal Norway and northern parts of continental Canada is about thirty degrees Celcius on average, even though they are the same latitude. 

In North America, the Gulf Stream is influential on the climate of the east coast of Florida, especially southeast Florida helping to keep temperatures warmer than in the rest of the southeastern United States in the winter. In summer the effect is opposite but small. The Gulf Stream makes the climate of offshore islands of Massachusetts, Martha's Vineyard and Nantucket, milder than that of Massachusetts Bay, which is isolated from its effects by Cape Cod. 
