Question

how does water kept cool in an earthen pot become cool during summers

Answer 1

Earthen pot water get cool Because, this is the process of evaporation.
Pot contains small pores or holes.
Cooling is caused by evaporation.When water evaporate from small pores it gets cool.

I hope it helps u
tq

Answer 2

the earthen pots has large number of extremly small pores on its walls. the water vapour evaporates continuously taking the earthen pots as well as the water.so it remains cool