What you are looking for is called the wet bulb temperature, which accounts for humidity and it’s effect on “perceived temperature.” It’s why those of us who live in the desert say “At least it’s a dry heat!”

So a “wet bulb” temperature is the reading on a thermometer when the bulb is wet and in the shade. In a less humid environment the rate of evaporation will be greater, and therefore the cooling effect will also be greater.

This is why a dry heat feels less intense, because the less humid environment makes our bodies self cooling method (sweat which evaporates) more effective.