Climate and Its Causes

The weather is the condition of the atmosphere at a specific time and place. The climate is the average weather of a region over an extended period of time. If you travel around the world, you will find many different climates.

Temperature and precipitation are the most important factors that impact climate. Temperature is influenced by latitude, altitude, large bodies of water, and ocean currents. Precipitation is influenced by winds and mountains.

The latitude of a region affects temperature. The sun’s radiation is most concentrated at the equator, resulting in warm temperatures. In polar regions, temperatures are much colder because the same amount of energy is spread across a larger amount of land.

Regions that are located at higher altitudes experience cooler temperatures. The air on top of a mountain is much cooler than the air at the base of a mountain because air temperature gets colder as you move to higher elevations in the troposphere.

Oceans and large lakes influence the climate. Water heats and cools more slowly than land, helping moderate the temperature of nearby land. The California coast has mild temperatures due to warm air blowing from the Pacific Ocean.

The ocean has surface currents that help distribute temperatures around the globe. Polar currents carry cool water toward the equator, and tropical currents carry warm water away from the equator. For example, the Gulf Stream creates warm air temperatures around southern Iceland and significantly impacts the climate of this region.

Prevailing winds blow primarily in one direction and influence the moisture in a region. Winds that travel across water are humid because they carry water vapor. Winds that travel across broad regions of land tend to be dry.

Mountains play a role in the climate. Moisture-laden clouds that run into mountains are pushed upward. As the clouds cool, rain or snow occurs. When the clouds move down the other side of the mountains, the dry air creates a desert climate. This effect is called a rain shadow.

Seasonal weather occurs because the Earth is tilted on its axis as it rotates around the sun. Throughout the year, the Northern and Southern hemispheres will be either pointing toward or away from the sun. Land near the equator has year-round warm and humid climates, while regions further from the equator experience more dramatic temperature changes.