Latitude is a critical factor in defining tropical climate zones, which are predominantly situated near the equator.

Latitude is a geographical measurement that indicates the distance of a point north or south of the equator, expressed in degrees. The equator itself is positioned at $0^\circ$ latitude, serving as the midpoint between the North and South Poles. Tropical climate zones are generally found between $23.5^\circ$ North, known as the Tropic of Cancer, and $23.5^\circ$ South, referred to as the Tropic of Capricorn. Collectively, this area is commonly referred to as the “tropics.”

The influence of latitude on these climate zones is closely associated with the tilt of the Earth and its orbit around the Sun. The Earth’s axis is tilted at an angle of approximately $23.5^\circ$ relative to its orbital plane. This tilt, along with the Earth’s rotation, results in the tropics receiving the most direct sunlight throughout the year. Consequently, these regions experience consistently high temperatures and substantial rainfall, which are hallmark features of a tropical climate.

The intensity of sunlight is greatest at the equator and diminishes as one moves toward the poles. This phenomenon occurs because the sun’s rays travel a shorter distance through the atmosphere at the equator compared to higher latitudes. As a result, less energy is lost, and the tropics receive more heat at the Earth’s surface. In fact, average temperatures in these areas typically exceed $18^\circ C$ year-round.

Moreover, the elevated temperatures in the tropics lead to increased evaporation rates, resulting in high humidity levels in the air. This humidity, coupled with the warm temperatures, often produces frequent and intense rainfall, which is another defining characteristic of tropical climates.

In summary, latitude is essential in determining the location and attributes of tropical climate zones. The tropics, situated near the equator, receive the most direct sunlight, leading to high temperatures and significant rainfall, which together characterize their tropical climate.