Why is water cooler...?

Question

...than air

Answer 1

water evaporates into the air, which cools the water, as it takes energy for the evaporation.

Answer 2

it isn't actually colder than air, its just that there is more particle density in water than there is in air so it absorbs heat from your body at a greater rate because all the particles are interacting with your skin instead of just a few that would be in air.

However, water tends to change its temperature slower than air, so if it is afternoon and the air is really warm, the water may be cooler because it is still regaining the heat that it lost overnight.

Answer 3

Water is not necessarily cooler than air.  It is slower to heat up and cool down than air, so in the winter it is often warmer than the air and in summer it is often cooler.

Answer 4

When you state "cooler" I assume you are referring to the thermal energy per unit water compared to the thermal energy per unit air. The specific heat capacity of water is higher than air meaning that per degree water stores more energy than air. The forementioned fact also means that the temperature of air can change faster and easier than water.