If you live near the coast, you may know how different a swim in the ocean feels in December than it feels in July. Temperatures in the surface zone vary with latitude and the time of year. Surface temperatures range from 1°C near the poles to about 24°C near the equator. Parts of the ocean along the equator are warmer because they receive more direct sunlight per year than areas closer to the poles. However, both hemispheres receive more direct sunlight during their summer seasons. Therefore, the surface zone is heated more in the summer.

Why are parts of the ocean along the equator warmer than those closer to the poles?