The trade wind is a wind that blows throughout the year in the tropics, a broad belt around the equator. In the northern hemisphere, it blows from the northeast to the equator, and in the southern hemisphere, it blows from the southeast to the equator. The sun, being directly overhead, is very strong and heats up the air in the equatorial region. The warm air automatically rises up, reducing the atmospheric pressure and allowing the surrounding air to flow in towards the equator. This flow of air is called the ‘trade wind’.