The oceans cover 71 percent of the surface of the Earth, which greatly exceeds the planet's land area, according to the Global Development Research Center. Temperatures can change quickly and dramatically over land, while ocean waters diffuse the effects of temperature change. Heat from the sun can penetrate only the thin upper crust of the land, while the ocean can absorb more heat and cold, making its temperature different from that of the land. It can maintain that temperature after the land has heated up or cooled down. For example, land near an ocean can heat up quickly when the sun rises and warm the air above it. The ocean, however, will remain cool from the night before.
Horizontal currents are another factor in the temperature difference in ocean air. Ocean currents can increase or reduce air temperature, the United Kingdom Environmental Change Network reports. Heated or cooled air moves along with the water for many miles. When the air reaches a land mass, it heats or cools the land, making a cool place feel warmer or a warm place feel cooler, according to the Missouri Department of Natural Resources.
Typically, along the western side of all continents, including South America and North America, Europe and Africa, currents flow from the north and south toward the equator, the solcomhouse website reports. These are considered cold currents, because they bring cold air from the north and south poles into the tropical regions. The eastern side of the continents has the opposite effect. The currents flow from the equator to the poles. These are warm currents because they bring warm air from the tropical regions toward the poles. One current of this type is the Gulf Stream, flowing from the Gulf of Mexico toward the British Isles.
The air around the Arctic, Southern and Indian oceans remains cold throughout the year, because the main currents in the regions run around the poles and do not mix with warmer currents. Air temperatures in the Indian Ocean are warmer in the east than in the west and the temperature drops are it heads toward Antarctica.