This past Memorial Day weekend, Mid-Missouri saw comfortable conditions as sunshine and warmer temperatures took over. One of the most notable factors that lead to such pleasant feeling temperatures was the low humidity levels.
Dewpoints this past weekend only reach into the upper 40s and lower 50s leading to a drier atmosphere. As the week continues heading towards this upcoming weekend, winds out of the south look to introduce more moisture into the environment raising dewpoints back into the lower 60s.
In drier environments, sweat on the surface of the skin can evaporate efficiently leading to a cool down for the body. This process helps regulate body heat. When there is increased moisture in the environment, the process of evaporating sweat decreases drastically meaning less cooling for the body. This leads to an increase in the likelihood of heat related illnesses.
When many people hear evaporation, they first think of heat. In order to change a liquid from a liquid to a gas, heat must be used to change this state of matter from one form to another. This leads to evaporation creating a cooling effect on the air or surface nearby. The reason the temperature feels cooler during a windy day as opposed to a windless day with the same temperature is due to an increase in evaporation efficiency.