The main factor determining a region's climate is __________.

Option B

Many factors influence the climate of a region. The most important factor is latitude because different latitudes receive different amounts of solar radiation.

The maximum annual temperature of the Earth, showing a roughly gradual temperature gradient from the low to the high latitudes.

• The Equator receives the most solar radiation. Days are equally long year-round and the Sun is just about directly overhead at midday.
• The polar regions receive the least solar radiation. The night lasts six months during the winter. Even in summer, the Sun never rises very high in the sky. Sunlight filters through a thick wedge of atmosphere, making the sunlight much less intense. The high albedo, because of ice and snow, reflects a good portion of the Sun's light.

Temperature with Latitude

It's easy to see the difference in temperature at different latitudes in the Figure above. But temperature is not completely correlated with latitude. There are many exceptions. For example, notice that the western portion of South America has relatively low temperatures due to the Andes Mountains. The Rocky Mountains in the United States also have lower temperatures due to high altitudes. Western Europe is warmer than it should be due to the Gulf Stream.