Overall, much of Europe enjoys a relatively mild climate, at least when compared with other locations throughout the world lying at the same latitude. This is primarily due to the Atlantic Ocean's warm Gulf Stream current, which exerts a moderating effect on a significant portion of the continent, particularly its westernmost half. Additionally, the continent's landforms, including mountain ranges such as the Alps and Pyrenees, alter the climates of certain areas. Europe's climates and corresponding weather can be roughly divided into six categories, based on geography.