Understanding Humidity - Why Humid Days Are Warm and Sticky

Many weather experts insist on being absolutelysaturation to occur at a certain temperature.
accurate in defining terms. For most peopleRelative humidity is expressed in percentages and
though, the simpler the explanation about humidityis again a useful tool when predicting the weather.
the better. In simple terms, humidity is a measureFor rain to occur, relative humidity should be at
of the amount of water vapor in the air. The100%.
truth is that much of the earth's surface isThis is all well and good for weather forecasters
covered with water, millions of cubic miles of it.and specialists. Average individuals though would
Only a very small fraction of that is water vapor.be more likely to wonder about the connection
The amount of water vapor however at anybetween high humidity levels and body
given time is a valuable tool in weathertemperatures. When conditions are humid, we
forecasting.often feel warm and uncomfortable. This is
How did water vapor get into the air anyway?because body temperature is regulated by
Part of understanding humidity is also knowing theperspiration. When the saturation point has been
basic concept of evaporation. When there isreached, human sweat cannot effectively
sufficient thermal energy, kinetic energy isevaporate, thereby leading to the familiar feelings
transferred to water molecules on earth, therebyof discomfort on a humid day. In some cases, we
allowing them to break free from their liquid formmay even feel languid or lazy on a humid day.
and evaporate. More water therefore tends toThis happens when the environment is too warm
rise up on hot days simply because there isfor the skin to release heat.
substantial thermal energy.Understanding humidity can also now help us
Once up there, a certain saturation point has tounderstand why we need humidifiers and
be reached for precipitation to be possible. Indehumidifiers. It is estimated that humidity should
other words, when water vapor is too much at abe at about 30% to 60% to keep comfortable.
certain temperature, rain might fall. DifferentThe mid point between this range is the ideal
temperatures come with different saturationfigure. In many offices therefore, air conditioning
points.set correctly is important to ensure maximum
One term that is vital to understanding humidity iscomfort and performance.
relative humidity. If you often listen to weatherUnderstanding humidity need not be rocket
reports, you are likely to hear this term. Relativescience. Although humidity is really quite
humidity is simply the amount of current watercomplicated, it is enough to know what it is and
vapor compared to the amount needed forwhy it is important to know about it.