The ability to sense humidity and wetness is an important attribute in the animal kingdom. For many insects, discriminating between dryness and wetness is vital for procreation and survival. Sensing wetness is also critical for humans, for both behavioral and autonomic adaptations. ~ English physiologist Davide Filingeri et al
There are no specific skin receptors for sensing moisture. Yet there is a distinct feeling we get when touching something wet.
Wetness is a perceptual illusion: a mental construction through intricate multisensory integration. We learn to perceive wetness through experience.
The human sense of humidity is temperature dependent. Whereas warm wetness is a modest sensation, moisture is keenly felt in the cold. This difference is an evolutionary outcome. Being soaked in warmth can be soothing. In contrast, getting soggy when cold rapidly robs the body of heat, and so represents an environmental hazard.