Close
  • Podcasts
    • Grammar Girl
    • Curious State
    • Get-Fit Guy
    • Money Girl
    • Project Parenthood
    • Relationship Doctor
    • Modern Mentor
    • Nutrition Diva
    • Savvy Psychologist
    • Who Knew?
    • Unknown History
    • Ask Science
  • Books
  • Categories
    • Health & Fitness
    • House & Home
    • Parenting
    • Relationships
    • Pets
    • Education
    • Tech
    • Productivity
    • Business & Career
    • Money & Finance
  • Offers
  • About QDT
What's Hot

How to prepare for potential layoffs

August 9, 2022

Insurance, Budget, and Long-Term Storage: What to Consider Before Committing to a Loft Conversion

August 9, 2022

Jessie Stephens takes us to the Beginning of the End

August 9, 2022
Facebook Twitter Instagram
Quick and Dirty Tips ™
  • Podcasts
    • Grammar Girl
    • Curious State
    • Get-Fit Guy
    • Money Girl
    • Project Parenthood
    • Relationship Doctor
    • Modern Mentor
    • Nutrition Diva
    • Savvy Psychologist
    • Who Knew?
    • Unknown History
    • Ask Science
  • Books
  • Categories
    • Health & Fitness
    • House & Home
    • Parenting
    • Relationships
    • Pets
    • Education
    • Tech
    • Productivity
    • Business & Career
    • Money & Finance
  • Offers
  • About QDT
Facebook Twitter Instagram Pinterest
Quick and Dirty Tips ™
You are at:Home » How Do Meteorologists Calculate ‘Feels Like’ Temperature?
Ask Science

How Do Meteorologists Calculate ‘Feels Like’ Temperature?

Why are the actual temperature and the 'feels like' temperature sometimes so different? How do meteorologists know what the temperature will feel like near you? Ask Science explains.

By Sabrina Stierwalt, PhDJanuary 31, 2019No Comments4 Mins Read
Facebook Twitter Pinterest LinkedIn Tumblr Email
 Apple Podcast Page  Spotify Podcast Page  Google Podcast Page  Sticher Podcast Page
Share
Facebook Twitter Pinterest WhatsApp Email

Meteorologists talk not only about what the temperature will be outside, but also what that temperature “feels like.” Why are these numbers sometimes so different? How do meteorologists know what the temperature will feel like to you?

Although numeric, temperatures are not universal. Most of us have a sense of what a temperature of 75 degrees Fahrenheit means, but add a brisk wind and you will feel colder. Raise the humidity and the temperature your body experiences feels a lot higher too. Precipitation and cloud cover also play a role in making that 75 degrees a more relative experience. So how are “feels like” temperatures calculated?

What is the heat index?

A simple measure of how a temperature of 85 degrees Fahrenheit, for example, will likely feel different in Houston, Texas versus Los Angeles, California is the heat index. The heat index combines the temperature and a measure of the relative humidity to give a better indication of how hot that temperature will actually feel.

On a hot day, our bodies sweat to cool down. In a low humidity, dry environment, that sweat is quickly evaporated into the air leaving us feeling effectively cooled. In humid locales, the air is already full of moisture and so our sweat evaporates more slowly (or not at all), leaving us feeling hotter.

The heat index combines the temperature and a measure of the relative humidity to give a better indication of how hot that temperature will actually feel.

Cold air can hold less water vapor so as temperatures decrease, eventually a temperature called the dewpoint is reached when the air is too cold to hold anymore moisture. Since water vapor can no longer remain in the air as humidity, it instead begins to condense on surfaces.  The temperature and the dewpoint together give the relative humidity, a measure of how much moisture is in the air relative to how much moisture the air could potentially hold. That relative humidity, combined with the temperature, then determines the heat index or an estimate of how hot the air actually feels.

So 85 degrees at 10% humidity, the temperature feels closer to 79 degrees, but at 90% humidity, it will feel closer to 100 degrees outside.  You can find the heat index in your city without actually doing any math thanks to online heat index calculators like those from the National Weather Service and the The Washington Post.

What is the windchill factor?

On the other end of the temperature spectrum is the windchill factor. Wind can cause sweat from our bodies to evaporate faster and can carry heat away from us quickly to make us feel colder.  Thus, for example, a temperature of 75 degrees can feel more like 65 degrees with windspeeds of 60 miles per hour.

How do you estimate a “feels like” temperature?

When a weather service makes a prediction about what a temperature will feel like, they typically include these basic measurements of the heat index and the windchill factor. A more complex estimate comes from the metric established in the 1990s and patented by Accuweather called the RealFeel Temperature. Their model includes heat index and windchill, but also other weather factors like cloud cover or UV index, sun intensity, visibility, and ground cover. They further incorporate expected heat transfer rates across an average sized human body with an average metabolism. And they assume the person is dressed appropriately for the weather.

Ultimately, “feels like” temperatures are an effort at understanding and quantifying the human response to temperature, a relationship with multiple complicating factors.

Ultimately, “feels like” temperatures are an effort at understanding and quantifying the human response to temperature, a relationship with multiple complicating factors. For starters, I can sit in a conference room in a scarf and sweater while my colleague next to me is comfortable in his t-shirt. Some of this difference comes down to our varying metabolisms—how fast we burn calories to produce heat and how fast that heat is dissipated over the surface area of our bodies. Our bodies may prefer different temperatures as well, like when a person is said to “run hot” or “run cold.”

So while there is still much estimation involved in determining “feels like” temperatures, they do a pretty good job of preparing us for what the weather has in store. And as we heard from meteorologist Morgan Miller in an earlier episode, local weather forecasters usually know what estimates work best for their region and can combine that knowledge with their personal experience to give you the best “feels like” estimate.

Disclaimer

Please note that archive episodes of this podcast may include references to Everyday Einstein. Rights of Albert Einstein are used with permission of The Hebrew University of Jerusalem. Represented exclusively by Greenlight.

Sabrina Stierwalt, PhD
  • Twitter
  • Pinterest

Dr Sabrina Stierwalt earned a Ph.D. in Astronomy & Astrophysics from Cornell University and is now a Professor of Physics at Occidental College.

Add A Comment

Comments are closed.

Don't Miss

How to prepare for potential layoffs

By Rachel CookeAugust 9, 2022

Hey, it’s Rachel Cooke, your Modern Mentor. And today we’re gonna acknowledge the elephant in…

Insurance, Budget, and Long-Term Storage: What to Consider Before Committing to a Loft Conversion

August 9, 2022

Jessie Stephens takes us to the Beginning of the End

August 9, 2022

Why Don’t People say ‘You’re Welcome’ Anymore?

August 8, 2022
Stay In Touch
  • Facebook 12K
  • Twitter 25.7K
  • Pinterest 18.5K
  • Instagram 123K
  • YouTube 23K
  • Vimeo 11.2K
Our Picks

How to prepare for potential layoffs

By Rachel CookeAugust 9, 2022

Insurance, Budget, and Long-Term Storage: What to Consider Before Committing to a Loft Conversion

By Diane HuttonAugust 9, 2022

Jessie Stephens takes us to the Beginning of the End

By Editor, Relationship DoctorAugust 9, 2022
Demo

Subscribe

 Apple Podcast Page  Spotify Podcast Page  Google Podcast Page  Sticher Podcast Page

Books

Don't miss

Never miss another tip! Join our list to get updates from your favorite hosts delivered straight to your inbox
Sign Up
ABOUT US
logo-img

Whether you want to manage your money better, rock your professional life, stay fit and eat healthy, or discover the keys to better mental health, Quick and Dirty Tips delivers short-form podcasts and articles every week to keep you at the top of your game, usually in ten minutes or less!

Email: contact@quickanddirtytips.com

QUICK LINKS
  • Health & Fitness
  • House & Home
  • Parenting
  • Relationships
  • Pets
  • Education
  • Tech
  • Productivity
  • Business & Career
  • Money & Finance
  • How to listen
  • Privacy notice
  • Ads & Cookies
  • Terms of Use
  • About QDT
  • Our Hosts
OUR PICKS

How to prepare for potential layoffs

August 9, 2022

Insurance, Budget, and Long-Term Storage: What to Consider Before Committing to a Loft Conversion

August 9, 2022

Jessie Stephens takes us to the Beginning of the End

August 9, 2022
Facebook Twitter Instagram
Copyright © 2022 Macmillan Publishing Group, LLC. Quick & Dirty Tips™ and related trademarks appearing on this website are the property of Mignon Fogarty, Inc. and Macmillan Publishing Group, LLC.

Type above and press Enter to search. Press Esc to cancel.