Western Europe is the region comprising the western part of Europe. Though the term Western Europe is commonly used, there is no consensus on which countries comprise it.
Significant historical events that have shaped the concept of Western Europe include the French Revolution, the Industrial Revolution, the two world wars, the Cold War, the formation of the North Atlantic Treaty Organization and the expansion of the European Union.
The climate of Western Europe varies from subtropical and semi-arid in the southern coast of Italy, Portugal and Spain to alpine in the Pyrenees. The Mediterranean climate of the south is dry and warm. The western and northwestern parts have a mild, generally humid climate, influenced by the North Atlantic Current. The CIA classifies these seven countries as belonging to Western Europe: Belgium, France, Ireland, Luxembourg, Monaco, Netherlands and United Kingdom.