Which States have the highest relative humidity? Which countries are the most humid?
Which state is more humid?Is it Florida?Louisiana?What about Hawai'i?None of the above is the answer.Alaska has the highest humidity over the course of the year.The cold, frozen north is more humid than most southerly states.Is this a trick question?Yes and no.
You are likely to be presented with the temperature, cloud cover, relative humidity, and precipitation when you watch a local newscast or look at a weather app on your phone.Before the word humidity, note the term relative.The confusion lies here.The relative humidity is just that.The amount of water in the air is compared to how much air can hold it.It is reported as a percentage between zero and 100%.The units are comforting to us because they don't require any special scientific understanding to know that 50% is twice as much as 25%.
The easy part ends here.As air warms up, it can hold more water.As air cools down, its ability to hold humidity decreases.Think of it as a sponge.Warmer air can hold more water.Colder air can hold less water than a bigger sponge.The warmer air holds more humidity if the sponges are half filled to capacity.We say that the relative humidity is 50%.
An 80F airmass that is 50% full of water vapor is shown as a sponge in a graphic that shows a 50% saturated air mass.This shows why using relative humidity is not a good metric.There are exceptions to this rule.The cooler airmass contains more water than the warmer one, even though they both report 50% relative humidity.
The trajectory of temperatures throughout the day is another aspect.Most of the time, the air is cooler in the morning and warmer late afternoon.As the temperature rises and falls, the relative humidity changes dramatically because of the amount of water in the air.There is a situation where the city has a high relative humidity at one time of the day and a low relative Humidity at another.
There are a number of ways to measure the air's humidity.The most popular is the dew point.Dew point is a measurement that most people can relate to.The minimum temperature an airmass can achieve is represented by the dew point, which is a temperature value.The diagram shows the temperature if the dry part of the sponges were removed.
Specific humidity, mixing ratio, and vapor pressure are not discussed here.
The dew point numbers represent handy guides for determining how much humidity is in the air.It's very oppressive to have a dew point over 75F.It's the amount of water in the air that makes you sweat.A moist dewpoint is over 70F.This is a common value in the southeast during the summer months.It starts to feel humid at a dew point over 60F.Dew points under 30F feel dry.
Alaska is the most humid state.This is due to the low temperatures.A cold airmass can't hold a lot of water.Alaska has the lowest average dew point of all 50 states.This is a truer reflection of the regime.
The maps show the average annual relative humidity and annual dew point.You would be forgiven for scratching your head if you only saw the first map.Most people would expect the desert Southwest to look like it.The second map shows areas that are more humid.