You’ve probably heard the terms “dew point” and “humidity” used when listening to the weather forecast and wondered how they are different. What’s the difference between dew point and humidity?
The main difference between humidity and dew point is that dew point is affected by temperature, while humidity is not. As the temperature decreases, the dew point also decreases. Humidity remains constant regardless of temperature changes. People often think that they are experiencing higher humidity levels than they actually are.
As a result, they may take steps to reduce the humidity in their environment, when what they really need to do is lower the temperature. Humidity vs dew point can actually be quite interesting to learn.
You’re sitting in your living room, feeling sticky and miserable. The temperature outside is sweltering, and the humidity is through the roof.
You turn on the news, only to hear that the weatherman is calling for even more of the same in the days to come.
At this point, you might be wondering what exactly is the difference between dew point and humidity; and more importantly, how can you use this knowledge to make yourself more comfortable during climate fluctuations.
So if you want a real judge of just how “dry” or “humid” it will feel outside, look at the dew point instead of the RH. The higher the dew point, the muggier it will feel.
Weather.gov
The relationship between relative humidity and dew point is very important when interpreting weather reports and making decisions about activities such as farming, construction, and day-to-day activities.
What’s the Difference Between Humidity & Dew Point?
The dew point is a measure of the amount of water vapor present in the air. The higher the dew point, the more water vapor is present and the muggier it feels. Humidity, on the other hand, is a measure of how much moisture is actually present in the air.
If you’ve ever stepped outside on a humid day and felt immediately sticky, that’s because humidity refers to actual moisture content, rather than just water vapor.
In general, areas with high humidity will also have high dew points, but not always. For example, desert climates can have very low humidity levels, even though there may be a lot of water vapor in the air.
Knowing the difference between dew point and humidity can help you to better understand why you’re feeling sticky on hot summer days, perhaps even helping you to find ways to stay cool.
So next time you’re sweating bullets while sitting in your living room, take a moment to check the news or weather website for dew point and humidity readings. It just might give you some relief.
What Is Considered a Comfortable Dew Point?
As an example, if the air temperature is 70 degrees Fahrenheit (21 degrees Celsius) and the dew point is 30 degrees Fahrenheit (-1 degree Celsius), then you can expect it to be comfortable because there isn’t as much water vapor in the air so it won’t be as humid.
On the other hand, if the air temperature is 70 degrees Fahrenheit (21 degrees Celsius) and the dew point is 60 degrees Fahrenheit (15 degrees Celsius), then you can expect it to be quite humid because the air isn’t able to hold all of the water vapor that it contains resulting in condensation.
What Is Dew Point When It Rains?
If the relative humidity is high then it means that there is a lot of moisture in the air and it is more likely to rain. If the relative humidity is low then there is less moisture in the air and it is less likely to rain. Dew points are commonly reported alongside temperatures during weather reports on television and radio.
They are also often included on weather maps shown on websites and in newspapers.
Knowing both the temperature and dew point can give you a good indication of what kind of weather conditions you can expect.
Dew points are measured using a psychrometer or hygrometer.
What Is the Highest Dew Point Ever Recorded?
The answer may depend on who you ask and where they are located. The Guinness World Record for the highest dew point was set in Dhahran, Saudi Arabia on July 8, 2003. The temperature was 107.6 degrees Fahrenheit with a dew point of 95 degrees, giving it a relative humidity of 90%.
However, there are reports of even higher dew points being recorded in other parts of the world.
For example, in December 2015, the city of Bandar Mahshahr in Iran reportedly had a temperature of 109.8 degrees Fahrenheit with a dew point of 108 degrees, giving it a relative humidity of 99%.
While these temperatures may be record-breaking, it’s important to note that they are not necessarily indicative of the highest dew points that can occur naturally.
In fact, the highest naturally occurring dew point is thought to be around 100 degrees Fahrenheit.
This occurs when air is saturated with water vapor and can no longer hold any more moisture.
So while the temperatures mentioned above may be record-breakers, they are not necessarily indicative of the highest dew points that can occur naturally.
What Is the Ideal Humidity in a Home?
According to the EPA, the ideal indoor humidity level should be between 30-50%. Anything above 60 percent is too humid, and anything below 30 percent is too dry. The ideal humidity level will vary depending on the season and the region you live in.
In general, homes in warm climates should aim for the lower end of the range, while homes in cold climates should aim for the higher end.
You can measure the humidity in your home with a hygrometer, which is a relatively inexpensive tool that is widely available online and at most hardware stores.
Maintaining the ideal humidity level in your home can improve your comfort level, help to prevent health problems, and extend the life of your furniture and electronics.
How to Increase Indoor Humidity
To increase humidity levels in a home, one can purchase a humidifier that will add moisture to the air. If the room is small, boiling water on the stove can also help.
Various problems can occur when levels of humidity are very low, including:
- Static electricity
- Chapped lips
- Irritated eyes
- Increased respiratory infections and other illnesses
- Dry air can also aggravate allergies and asthma symptoms.
- Wood furniture, wood floors, and other household items to crack and split
There are several ways to increase the humidity in your home, so take your pick and enjoy the benefits of higher indoor humidity levels.
How to Reduce Indoor Humidity
Reducing indoor humidity is important for several reasons. High humidity levels can lead to the growth of mold and mildew, which can cause serious health problems.
In addition, high humidity levels can make it difficult to breathe and can cause condensation on walls and windows.
Electronics and wooden furniture are also susceptible to moisture damage from high humidity.
Therefore, it is important to reduce indoor humidity levels in order to protect your health and your belongings.
There are several ways to reduce the humidity level indoors. Let’s take a look at a few of them here:
- Install a dehumidifier.
- Ventilate the home by opening windows and doors.
- Use fans to circulate the air.
- Adjust the humidity level on your thermostat.
- Clean or replace your air filters regularly.
Running an exhaust fan during and after taking showers and baths will help reduce moisture accumulation in the air as well.
Final Thoughts
In this article, we’ve learned the differences between humidity and dew point and the importance of both. When we understand dew point and humidity, we are more able to control our indoor environment as well as to be more prepared for confronting the outdoor climate.
Sources
- Live Science
- National Oceanic and Atmospheric Administration (NOAA)
- Weather.gov
- United States Environmental Protection Agency (EPA)
Trina Greenfield, Author
SmackDown Media LLC
LinkedIn
About the Author:
Trina Greenfield, the owner of SmackDown Media LLC, is passionate about providing information to those interested in the air quality in and around their homes. Trina writes content about things she’s passionate about, such as safe, in-home air, educational platforms for children and adults, as well as all things family-related.
