Tropical climates are characterized by consistently high temperatures, with minimal variation throughout the year. These climates are predominantly found near the equator, where the sun’s rays strike most directly, leading to elevated average temperatures. Typically, the temperature range in these regions falls between $20^\circ C$ and $35^\circ C$.

In tropical areas, temperature fluctuations between day and night, as well as across different seasons, are minimal. This stability is due to the relatively constant amount of sunlight that these regions receive throughout the year. Additionally, the length of daylight remains fairly uniform, with approximately equal hours of daylight and darkness. This consistent exposure to sunlight contributes to a stable, warm climate all year round.

However, there can be some temperature variations within the tropics, influenced by factors such as altitude and geography. For instance, mountainous regions may experience cooler temperatures due to their higher elevation. Similarly, coastal areas may enjoy slightly cooler conditions owing to the moderating effects of the ocean.

Despite these regional differences, the hallmark of a tropical climate is its warmth. Even during the coolest months, temperatures seldom drop below $18^\circ C$. This enduring warmth, coupled with often high humidity levels, distinctly sets tropical climates apart from other climate types.

In summary, while geographical factors can lead to some variations, the typical temperature range in tropical climates remains between $20^\circ C$ and $35^\circ C$. This consistent warmth, a defining characteristic of the tropics, is primarily due to the region’s proximity to the equator and its steady exposure to the sun’s rays.