Due to the moderating influence of the sea.
Explanation
The climate of a region is significantly influenced by its distance from the sea, a concept known as continentality versus maritime influence. Water bodies have a higher specific heat capacity than land, meaning they heat up and cool down much slower. This property allows oceans to moderate the temperature of adjacent landmasses.
Analysis:
- The Peninsular region of India is surrounded by water bodies on three sides: the Arabian Sea to the west, the Bay of Bengal to the east, and the Indian Ocean to the south.
- This geographical configuration subjects the region to a strong maritime influence (equable climate). The sea exerts a moderating effect, preventing significant drops in temperature during the winter months and keeping the annual range of temperature low.
- In contrast, North India experiences a continental climate due to its distance from the sea, resulting in a distinct and well-defined cold season with significant temperature variations.
- While proximity to the Equator ensures that the region receives high insolation and remains generally warm, the specific characteristic of lacking a well-defined seasonal contrast (i.e., the absence of a sharp distinction between summer and winter temperatures) is primarily attributed to the moderating role of the sea.
Key Takeaway:
The moderating influence of the sea ensures that Peninsular India does not experience extreme thermal variations, resulting in an equable climate without a well-defined cold season.