Published February 23, 2024 at 5:47 p.m
Anyone who does outdoor activities in winter is familiar with the wind factor, also known as wind chill. This is now firmly anchored in our winter weather reports. Before you go out, you have to take into account the mercury but also the wind to avoid frostbite and hypothermia. The concept of wind cooling is not new; it originated in Antarctica in 1939.
It was Paul Siple, an American scientist who lived in Antarctica between 1939 and 1941, who wanted to understand the influence of wind on temperature. With the support of his assistant Charles Passel, he will analyze the rate of cooling of the water and the time it takes to freeze. You will take measurements in different wind and temperature conditions. Then they will make a connection between the heat loss of the water and the influence of the wind on the thin layer of warm air that envelops every living thing. They will be the first to use the term windshield factor or wind chill factor.
When the wind blows, it dispels this thin layer of heat that is on our skin. The body then has to use its energy to produce another. As the wind continually blows away these layers of heat, the skin cools down. We feel the cold even more strongly. Be careful, wind chill does not affect objects. It only affects living beings.
The lower the air temperature, the greater the effect of the wind. For example, if the air temperature is -5°C and we have a wind of 20 km/h, we will have a feeling of -11.6, a difference of less than 7. But if we have a temperature of -20°C With the same wind at 20 km/h we will feel like -30.5, a difference of more than 10.
However, the wind factor is a calculated value and not a measured value. The temperature is measured. So we can say that the air has a temperature of -20°C. For the wind factor we say that we have a feeling of -30, but without talking about degrees since it is a calculation and not a measurement. When the wind factor reaches -28, the risk of frostbite becomes moderate and exposed skin freezes within 10 to 30 minutes. When this value reaches -40, the skin freezes in 5 to 10 minutes, and at -48 in 2 to 3 minutes.
You can easily find the value of the wind factor on the MétéoMédia website or application. However, if you want to do the calculation yourself, here is the formula: 35.74 + 0.6215T – 35.75V0.16 + 0.3965TV0.16T: represents the temperature. V: represents the wind speed. Finally, is it easier to watch The Weather Network.
Every year in Canada, more than 80 people die from excessive cold exposure. While wind chill is something to consider in the winter, it's not the only factor you should worry about. The quality of your clothing and its insulating properties are also important. These should be able to keep your heat close to your body. Additionally, wet boots or clothing lose their ability to keep you warm. The shape of a person's body also influences the fight against colds. Tall, thin people freeze more quickly than smaller, rounder people.