What Is Humidity?
Humidity refers to the amount of moisture or water vapour in the air. It is measured in relative terms (comparing the wettest and dryest time of each day) and expressed in terms of a percentage. The higher the percentage, the more humid the weather.
Causes of Humidity:
Humidity arises from the natural phenomenon known as the water cycle. Under the sun's heat, water from the various water bodies (such as oceans, rivers and lakes) evaporates and become water vapour in the atmosphere. The level of humidity increases as the amount of water vapour in the atmosphere builds up.
As the water vapour rises up in the atmosphere, clouds are formed, which can be blown away by the winds. When it eventually rains, the accumulated water vapour returns to the earth's surface, which completes the water cycle.
It can thus be surmised that the cause of humidity is an interplay of these three factors: Water, Temperature and Wind.
Effects of Humidity:
A. In humid areas (such as the tropics):
1. A person tends to perspire more easily, especially under physical exertion. This results in a sticky and clammy feeling on the skin. Arising from heavy perspiration, it is necessary to drink water often to make up for the loss so as to replenish the body.
2. After washing, wet clothings will take a longer time to dry, although the presence of winds help.
3. Metal objects tend to rust faster as the moisture in the air facilitates the process of oxidation.
4. When kept in the cupboard for a long time, books and magazines get affected by mildew, while food, clothings and leather products turn mouldy. silica gel.
B. In arid areas (such as the deserts and during the winter season):
1. Even as a person exerts himself/herself, the perspiration coming out of the person's sweat pores evaporates into the air quickly. So, the skin feels dry.
2. When in the open, the lack of natural moisture in the air causes the external layer of the skin (the epidermis) to dry up quickly, resulting in cracked lips and peeling skin. To prevent this from happening, it is necessary to apply a moisturiser/moisturising cream onto the face, hands and other exposed parts of the body. It is also important to keep the body hydrated by drinking sufficient amounts of water. When indoors, humidifiers should be used to maintain a comfortable level of humidity. Another simple method is to leave bowls of water in the different rooms and let natural evaporation keep up the humidity level.
3. Due to the lack of humidity, which is often accompanied by the lack of wind, the air is more dusty. If there are a lot of pollutants and small particles in the air, smog is formed, which is bad for health.