Why does soil cool down quicker than water?

Soil does not have a higher specific heat than water.

Specific heat capacity, also known simply as specific heat (Symbol: C or c) is the measure of the heat energy required to raise the temperature of one gram of a substance by one Kelvin (or degree Celsius). Water has a specific heat of 1 calorie / gram / degree C.

The specific heat of dry is soil is ~ 0.2 calorie / gram / degree C or ~ 5 times lower than the specific heat of water. The specific heat of moist soil is the weighted average of the water and mineral components of the soil .