KNOXVILLE, Tenn. (WVLT) -- James Tomerlin asked, “How do you figure out the wind chill factor?” Since we’re getting into the time of year when Heat Index is a big talker, I want to go over each.
Both fall under the general category of “feels like temperature” because it is an estimation on how certain weather factors affect you.
Wind Chill takes into account the temperature and the wind speed, and assumes that certain wind speeds will make you feel colder.
Heat Index is about temperature and humidity, so the higher the humidity the warmer it feels to you.
They really don’t take into account anything else. There are 5 big factors on how it feels to you outside at any given point in the year.
1. Sunlight – direct sunlight will make you feel warmer, just like it heats up surfaces. The Heat Index does not take sunlight into account, so on a hot, humid day you definitely want to stay in the shade, or better yet indoors.
2. Wind – the wind can always be a cooling factor, it’s just in the Winter it’s especially evident in the Wind Chill. Evaporative Cooling is beneficial to you in the Summer, because as the wind blows and if your body is wet or sweaty, the evaporation of that moisture is a natural cooling process. That’s why a fan doesn’t actually cool down the temperature in the room, but it can cool down your body temperature.
3. Temperature – obviously this is the biggest factor, and is at the base of all of these BUT a hot day, in the shade, with a good breeze can be very comfortable. But, you still have to take into account the humidity.
4. Humidity – This is the amount of moisture in the air. When the humidity levels are low, your body is able to use Evaporative Cooling to sweat and dry naturally. But, the increased moisture in the air keeps the body warmer and ultimately makes it feel hotter to you.
5. Clothing – This is the one you can control. When we’re talking about a low Wind Chill, covering exposed skin decreases the chances for issues like frost bite.