Wind chill, which is calculated as wind chill factor, is the measure of effect of wind on the temperature. This wind chill factor depends upon the atmospheric temperature and the speed of the wind. When you have calculated the wind chill temperature, you will notice that the wind chill temperature is usually less than the atmospheric temperature. This article on how to calculate wind chill will help you in calculating wind chill factor using simple formulas.
Calculating wind chill
The formula for calculating wind chill is given as:
Wind chill temperature = 35.74 + 0.6215 × T – 35.75 × V 0.16 + 0.4275 V 0.16
Another formula for calculating wind chill which was implemented by National weather service and which is used by United States and Canadian weather services is given as:
Wind chill temperature = 13.12 + 0.6215 × T – 11.37 V 0.16 + 0.3965 T V 0.16
In the above formulas,
- T is the temperature of air calculated in degree Fahrenheit or in degree Celsius
- V is the speed of wind calculated in miles per hour or kilometers per hour
If you want to calculate the wind chill factor, you need to calculate the temperature and speed of wind. These formulas are devised using standard engineering correlations of wind speed and heat transfer rate.
The old formula which was devised by National weather service which is not so popular nowadays is,
Wind chill temperature = 0.08173(3.71 V 0.5 + 5.81 – 0.25 V) (T – 91.4) + 91.4
- These calculations are quiet lengthy, so you need to use calculator for performing calculations.
- These formulas for calculating wind chill temperature are defined for calculating wind chill temperature at or below 50 degree Fahrenheit and the wind speeds above 4.8 kilometers per hour or 3.0 miles per hour.
- The chilling effect largely depends upon the changes in temperature, as the temperature decreases the chilling of any wind increases i.e. chilling effect is inversely proportional to the temperature.
Wind chill charts
- There are many tables or charts so that you can determine the wind chill temperature readily without performing any calculations. These charts for determining the wind chill temperature are designed by NWS or National weather service. You can search for these charts online as “NWS wind chill chart”.
- These charts represent the values of temperatures horizontally on the top and different values for the speed of wind vertically and the values of wind chill temperature are given in the form of matrix. This chart also indicates scales for frostbite times.
- To determine wind chill temperatures using these charts, find the approximate temperature on top of the chart for which you want to calculate the wind chill temperature. Read down until you reach the value of the appropriate wind speed.
- Now, locate the point of intersection of the temperature and the wind speed. The number that appears at this point of intersection is your wind chill factor or wind chill temperature.
Wind chill calculators
- Online calculators for calculating wind chill can also be used to calculate wind chill temperature.
- To calculate wind chill temperature using online calculators, you need to enter the values for temperature and wind speed either in degree Fahrenheit or degree Celsius and Mph or Kph respectively.
- By entering the values in the text boxes, click on the “calculate wind chill” button and the wind chill factor or wind chill index will be calculated.
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