The climate of the United States is influenced, among other things, by the formation and movement of air masses. Arctic, temperate, and tropical air masses migrate over the continent during certain seasons. At the same time, the masses formed over the oceans carry a lot of moisture to the continent, while the continental masses, on the contrary, are dry and contain a lot of dust.

The influence of the ocean on climate

The United States borders several oceans. The Pacific Ocean washes the western coast of the country, the Atlantic Ocean washes the eastern coast, and the Arctic Ocean borders Alaska in the north. The proximity of the ocean determines the high degree of air humidity in the coastal areas. This is most pronounced in the northwestern United States in Washington and Oregon. A typical maritime climate with rather mild winters and cool summers, as well as year-round precipitation, has formed here.

Ocean currents also play an important role in establishing the climate in certain coastal areas of the country. The Gulf Stream in the Atlantic Ocean has a warming effect on the western coast of the United States. The Alaskan current warms the waters of the northeastern Pacific Ocean and contributes to an increase in air temperature in southern and southwestern Alaska. The California and Labrador currents, on the other hand, have a cooling effect on the climate of the coasts.

Mountain systems and climate formation

The relief of North America has a significant impact on climate formation on the continent and in the United States in particular. The Cordillera mountain system is located in the west, which prevents the passage of air masses from the Pacific Ocean. These masses affect only a relatively small coastal zone in front of the mountains, and they practically do not penetrate deep into the mainland.

The Appalachian Mountains, which rise in the east of the continent, do not create serious obstacles to the penetration of air masses from the Atlantic. The flat terrain in the central part of North America ensures the seasonal passage of tropical masses from south to north and Arctic masses from north to south.