Fact Checked

What Is Humidity?

Helen Akers
Helen Akers

Humidity is the amount of moisture present in the air, and it can change depending upon the time of year and whether there is active precipitation. Relative humidity is the percentage of moisture that actually exists relative to the amount that could exist. Dew points reflect the temperatures where 100% humidity will occur.

There are certain regions that tend to have higher levels of moisture in the air than others. In general, cities that are located closer to the equator have higher dew points and feel more humid. A muggy feel is common in these cities, especially in the morning. Cities with high humidity and low dew points have more of an arid feel to them.

Moisture level in the air is measured as humidity.
Moisture level in the air is measured as humidity.

Air moisture is a key component of this measurement. When there is more moisture, there is a greater chance of precipitation, and storm activity tends to increase. For example, locations such as Florida in the United States tend to experience regular afternoon thunderstorms year round.

Cold air is not able to hold as much moisture. In many locations, cool morning temperatures often result in visible dew on plants and grass as the air releases water that it cannot hold.

Dew forms on plants when cold air cannot hold moisture.
Dew forms on plants when cold air cannot hold moisture.

Relative humidity indicates the percentage of air moisture. For example, a measurement of 30% relative humidity might indicate low levels, while 50 or 60% would indicate high levels. When precipitation occurs, these percentages typically approach 100%, which indicates full saturation.

The thickness of the air tends to be greater with higher levels of moisture. Besides a general feeling of mugginess, these higher levels can also make warm or cool temperatures feel more extreme. In humid locations, warm temperatures will feel warmer than the same temperatures in an arid climate. Likewise, cool temperatures in humid locations will feel much colder than the same temperatures in a dry area.

Coastal breezes can help circulate air and make it feel less humid.
Coastal breezes can help circulate air and make it feel less humid.

An example of this phenomenon can be seen in a location such as Florida. Residents of this state often put on sweaters and turn on their heat with temperatures as high as 50°F (10°C). The same temperature in a drier climate, such as the state of Colorado, might prompt those residents to turn off their heaters.

Coastal breezes can diminish the feeling of humidity. The breeze helps to circulate the air and remove some of its heaviness, while cooling temperatures. Cities that are located inland tend to maintain a stuffy feeling.

You might also Like

Discussion Comments


@manykitties2 - I hear you about the humidity. I can take a dry summer any day, but when the moisture starts to seep into the air things just get horrible.

If you are having trouble keeping your hair from frizzing a good idea is to invest in some styling products that contain silicone. The silicone really helps to smooth your hair out and prevents it from becoming totally unmanageable.

Another good idea is to find a leave in cream that is specifically made for humidity. Having your hair go wild in humid weather is pretty normal so there are oodles of products available for the purpose of protecting your hair.


I made the mistake last year of moving to a new city without checking what the local weather was really like. I glanced at the forecast now and then before I moved, but I really never checked anything like the humidity. I regret that because there is a huge difference in the way this city feels compared to how my old town felt during the summer.

It seems to me that when there is high humidity it feels like I can't stay dry. My hair frizzes and I constantly feel sticky. I really miss my drier climate.

The only thing I find that helps is air conditioning which seems to keep the humidity at bay. Unfortunately it does horrible things to my hydro bill.


@Oscar23 – I feel your pain. And, do you know what else happens when it gets that hot and that humid for several days at the time? I’m sure you do, but let’s enlighten all of the other folks out there.

You get big, humongous, noisy and downright scary electrical storms. You even might have a tornado or two thrown in. It’s very, very frightening.

The area where I am at is a big farming community, and so I pretty much am looking at a lot of fields from anywhere in my yard. Those fields are surrounded by forests.

You can literally see the storms coming at you across the fields, and it will certainly give you a new found respect for Mother Nature.

The lightning that comes with these storms often shoots straight down to the ground, and has horribly booming lightning that can shake your whole home.

We often have whole crops devastated by the fury that these storms bring. One up side – they help the humidity ease up quite a bit immediately thereafter.


I have an excellent answer to the question of what humidity is; it is pure misery, my friends.

I live near the coast of North Carolina and the past few summers have seen us with extraordinarily high humidity and heat. It’s nothing to reach a hundred and ten anymore throughout the summers here.

While the heat is bad enough, the humidity makes it worse. The temperature may read something like a hundred, but it’ll feel like its one fourteen. It’s miserable.

Humidity is sticky, uncomfortable and absolutely horrible to endure where I live when it’s at its worst.


I have learned that humidity calibration is typically difficult in any area outside of the lab when you get to specifics on humidity.

But you know what I think, whether or not it is being specifically and accurately calibrated (which I am sure is very important in some scientific matters unknown to me) I have never walked outside and thought, "Is it humid out here today?"

Now what I would like the humidity instruments to accurately calculate is just how big my hair is going to be that day secondary to the humidity. Talk about a great invention. They could come on the news and say something along the lines of: The humidity hair instrument says: “Do not even think about straightening your hair today." or "Possibility for straight hair today."

Let me know when that has been invented!


@wavy58 - I know what you mean about the humidity of Mississippi! I was from Kentucky (which can be rather humid I think from being bordered by the Ohio river), and decided to go play soccer at the a university in Mississippi.

Part of my reason for going there, was because I had visited the college in October and it was gorgeous. The sun was shining. There was no humidity. I thought it was great.

I did not think about how it would feel in August, which is when the soccer season starts!

However, I made it through the humid days of August in Mississippi, and now I live in North Carolina and people are always amazed at how the summer weather does not bother me. I always try to explain, "After playing soccer in Mississippi, it is difficult for me to be bothered by heat."


@John57 - I understand what you are saying when you comment on dry skin in areas of lower humidity.

Every year we camp for a week in the Colorado Rockies. While I look forward to the cooler temperatures and low humidity, I can tell a big difference in my skin after just one week.

All of my skin is much drier and I feel like I am constantly applying moisturizer or lotion to keep it hydrated.

I also notice a big difference in my hair. I have a lot of natural wave to my hair and sometimes in the hot, humid summers it can be difficult to control. When I am in an area with low humidity, my hair is much more manageable.


My sister moved from Nebraska to Arizona several years ago and one of the things she comments on the most is that they have very low humidity. She loves the weather there and doesn't mind the hot temperatures because of the lower humidity levels.

She remembers the hot, humid summers when you feel like you are still wet even after you have just taken a shower and dried off.

In Arizona they can have a 100 degree day, but because of the dry air with low humidity, it is easier to tolerate. In Nebraska we can have an 85 degree day with 90% humidity and it is almost unbearable to be outside for any length of time.

There is one advantage to having higher humidity levels with more moisture content in the air - your skin doesn't dry out as easily.


Living in the Midwest my whole life, I am very familiar with humidity. It doesn't matter if we have an extremely hot summer or a cooler one, if the humidity levels remain high it can be miserable.

Many times we turn our air conditioning on because of the high humidity and stickiness in the air more than the outside temperature itself.

Every day when they give the weather report, they tell you what the humidity ratio is. When it gets above 60, you know you are in for a muggy day. Sometimes the air is so thick that it feels like fog or haze.

Since I have lived with this my whole life, I am used to it, but people who visit from other places with much lower humidity never like it.


The morning after a humid summer day, dew always forms on the grass, flowers, and everything left lying on the ground. We pretty much have dew every morning during the hot summer months.

The dew drops remain on the grass until about 10:00 a.m. This keeps people from mowing their lawns in the cool morning hours. They have to wait until the sun has had enough time to evaporate the dew with its increasing heat.

Dew can cause rust on metal objects left lying outside. I always get onto my husband about leaving his tools out on the ground, because we know that dew will form every day. Most of them are very rusty now.


@lighth0se33 - I pass by Orange Beach on my way to Perdido Key, Florida. It has the same level of humidity, so I know what you’re talking about.

Sometime between noon and 3:00 p.m. every day, the area gets a thunderstorm. It usually rains, and there is always loud thunder and lightning. For this reason and to avoid the extreme humidity, I prefer to go to the beach early in the morning and around sunset.

Before the sun has had a chance to heat the sand, the early morning ocean breeze can impart a chill to the air. Sometimes I even need a light jacket while walking the beach in the morning. The same moisture in the air that adds to the cooling effect will later make the region feel much hotter than it actually is.


One of my favorite vacation spots is also one of the most humid. I love going to Orange Beach, Alabama in July, but if I’m not in the water, the humidity can be overpowering. This beach is about five minutes from Florida, so you can imagine the heat.

While I’m shopping inland, I become weak from the heat just by walking to and from my car. The heat rising from the asphalt in the parking lot amplifies the effect.

However, when I step onto the beach, I am immediately relieved by the strong ocean breeze. It blows all the time, and it takes the sting out of the extreme humidity.


I live in Mississippi, one of the most humid states in summertime. From June until September, ninety degree temperatures are accompanied by a heat index that exceeds 100 degrees. If you don’t have access to a pool or a lake, chances are you will be miserable outside.

I have a flower garden, but I have trouble working in it during the summer. The humidity makes me feel like I am wearing a big sweater and thermal underwear, even though I’m in shorts and a t-shirt. Often, there is no breeze to offer relief.

In August, the humidity makes our world so overwhelmingly hot that even the swimming pool doesn’t cool us off. The water feels like a hot tub, and you can actually feel hotter in it than on land. Lakes are better sources of cooling, because they are so large that they take longer to heat up than small bodies of water.

Post your comments
Forgot password?
    • Moisture level in the air is measured as humidity.
      By: Rido
      Moisture level in the air is measured as humidity.
    • Dew forms on plants when cold air cannot hold moisture.
      By: vencav
      Dew forms on plants when cold air cannot hold moisture.
    • Coastal breezes can help circulate air and make it feel less humid.
      By: iofoto
      Coastal breezes can help circulate air and make it feel less humid.
    • High humidity can cause severe thunderstorms to develop.
      By: valdezrl
      High humidity can cause severe thunderstorms to develop.
    • High humidity typically brings afternoon showers in Florida.
      By: SeanPavonePhoto
      High humidity typically brings afternoon showers in Florida.