Question

Why does temperature in Mumbai and Chennai not fall as low as it does in Delhi?

Answer 1

  since mumbai and chennai are nearer to water bodies,due to high specific heat capacity of water,the presence of a large amount of water is able to modify the climate of the nearby land areas,making them warmer in winter and cooler in summer.land and sea breeze are also set up because of this great moderating property of water.

Answer 2

Because Chennai and Mumbai are situated at the coast of sea which make the temperature equinox ( or equal ). That's why temperature does not fall or rise at very high level.