A clay water pot, also known as an "earthenware pot" or "un glazed clay pot," is a traditional method for storing and cooling water on hot sunny days. The process works through a process called evaporative cooling. The porous clay material of the pot allows water to slowly seep through its walls, which then evaporates into the air. As the water evaporates, it takes away some of the heat from the surrounding air, thereby cooling the water inside the pot.
To use a clay water pot to cool water, fill the pot with water and place it in a well-ventilated area, such as a balcony or terrace, where it will be exposed to the sun and wind. As the water in the pot evaporates, it will cool the remaining water inside. The water inside the pot will be cooler than the outside temperature, especially on hot sunny days.
It's worth noting that the clay pot should be unglazed, so the water can seep through the walls, it should be in a well-ventilated area to make the evaporation more efficient and should be covered to prevent debris and dust from getting in the water.