Before stepping out of the house, it’s important to know what kind of weather awaits you outside. The temperature outside can determine how comfortable you’ll be throughout the day when you are indoors or out and about. However, temperature alone may not always give the most accurate representation of the conditions outside. For instance, 70°F with low humidity can feel comfortable while the same temperature with high humidity might feel unbearable. The heat index and wind chill value are the two commonly used measures to determine the feels-like temperature, offering a more precise idea of what to expect when stepping outside.
The Heat Index: How Does it Work?
The heat index is a measure that takes into account both the temperature and the relative humidity. The higher the humidity, the harder it gets for the body to regulate temperature through sweat evaporation, causing the body to feel hotter than it would otherwise. When the body overheats, it can lead to heat exhaustion or even heatstroke, which can be fatal if left untreated. It’s essential to monitor the heat index to ensure the safety and well-being of yourself and anyone working or playing outside.
The Specific Formula for Calculating Heat Index
The heat index is calculated using a formula based on the temperature in Fahrenheit(T) and the relative humidity in percentage(H) as follows:
| T | H | HI |
|---|---|---|
| 80 | 40 | 82 |
| 85 | 45 | 88 |
| 90 | 50 | 94 |
| 95 | 55 | 103 |
| 100 | 60 | 114 |
| 105 | 65 | 127 |
| 110 | 70 | 141 |
The above table shows several examples of the heat index calculation, based on different combinations of temperature and relative humidity.
Ways to Stay Safe During High Heat Index Days
- Avoid outdoor activities during the hottest times of the day.
- Stay hydrated frequently.
- Wear light-colored, loose-fitting, and breathable clothing.
- Protect yourself from the sun with a wide-brimmed hat, and use sunscreen.
- Take breaks indoors or in shaded areas when possible.
Wind Chill Value: How Does it Work?
The wind chill value measures how cold the air feels when the wind is blowing. When the wind blows, it removes the warm air around your body, making it feel colder than the actual temperature reading. This makes the wind chill value an important component to consider before heading outdoors, especially during colder months.
The Specific Formula for Calculating Wind Chill Value
The wind chill value is calculated based on the air temperature in Fahrenheit(T) and wind speed in miles per hour(W) as follows:
| T | W(mph) | Wind Chill Value |
|---|---|---|
| 20°F | 20 | 4°F |
| 5°F | 25 | -22°F |
| 10°F | 30 | -13°F |
| -10°F | 40 | -38°F |
| -30°F | 60 | -68°F |
The wind chill value varies based on the combination of temperature and wind speed. The above table is an example of how the wind chill value is calculated for different temperature and wind speed combinations.
Ways to Stay Safe During Low Wind Chill Days
- Layer up with clothing that is warm and dry.
- Protect exposed skin, especially the face, from frostbite with hats, scarves, and gloves.
- Stay dry to reduce the risk of hypothermia.
- Monitor the temperature, and avoid outdoor activities when it’s too cold.
What Determines the Feels-Like Temperature?
Many factors aside from wind speed and relative humidity play a role in determining the feels-like temperature. These include:
- Altitude above sea level
- Intensity of radiant energy from the sun
- Physical exertion and level of clothing insulation
- Temperature of the surface next to your body (like a park bench or car seat)
How to Check the Feels-Like Temperature
Many weather websites and apps offer a separate section to find out the feels-like temperature. These platforms display the value of the heat index for hot and humid conditions and the wind chill value for cold and windy conditions directly. For instance, AccuWeather, The Weather Channel, and Weather Underground all offer up-to-date weather information, including the heat index and wind chill values.
Conclusion
Knowing the feels-like temperature is essential when planning outdoor activities. Depending on your location, you may need to take precautions to protect yourself from heat exhaustion, frostbite, and other cold-related illnesses. By understanding the differences between the temperature reading and the feels-like temperature, you can stay safe and comfortable no matter the weather.
Common Questions and Answers
- Q: What is the difference between temperature and feels-like temperature?
A: The temperature is a measure of how hot or cold the air is, while the feels-like temperature is a measure of how it feels being outside in the temperature, taking into account factors such as humidity and wind conditions. - Q: Is it safe to go outside when the wind chill value is low?
A: It is safe when you dress appropriately, wear a hat, scarf, gloves, and warm clothes. However, staying outside for too long can lead to frostbite or hypothermia. - Q: Is it safe to work outside when the heat index is high?
A: Working outside in high heat and humidity may lead to heat cramps, heat exhaustion, and eventually heatstroke. Take frequent breaks, stay hydrated, and limit outdoor activities during the hottest times of the day. - Q: What are the best ways to protect myself from the heat?
A: Wear light-colored and loose-fitting clothing, stay hydrated, take frequent breaks indoors, and limit outdoor activities during the hottest times of the day. - Q: Can you feel colder than the actual temperature?
A: Yes, especially when the wind is blowing, the air temperature feels colder than it typically would without the wind.
References
AccuWeather. (2021). Heat Index vs. Wind Chill: What’s the difference? Retrieved from https://www.accuweather.com/en/weather-news/heat-index-vs-wind-chill-whats-the-difference-2/607191
National Weather Service. (2021). Heat Index Chart. Retrieved from https://www.weather.gov/ama/heatindexchart
National Weather Service. (2021). Wind Chill Chart. Retrieved from https://www.weather.gov/safety/cold-wind-chill-chart