Dressing for the Wind Chill Factor

2 December 2015, 14:28

You’ve probably heard of the wind chill factor before, but how much notice do you actually take of it?

If you watch the weather forecast during the winter months, you’ll probably be familiar with the forecaster telling you what the temperature will be each day. You might also be aware of them telling you what it will actually feel like outside.

For example, at the time of writing the temperature at midday for the City of London was estimated to be 12 degrees Celsius. There was a gusty wind from the south-west at the time, and this made it feel more like 9 degrees Celsius.

Now let’s compare that with the Cairn Gorm Summit, the top of the highest mountain in the Cairngorms in the Scottish Highlands. On the same day at the same time, the temperature there was calculated to be -6 degrees Celsius. The wind was gusting up to 50mph from the west, and the actual conditions made it feel as if it was actually -17 degrees Celsius. As you can see, this is significantly different.

Of course, we’ve picked a low-lying city location and compared it to the top of one of the highest mountains in Scotland to make a point. However this is a good way of illustrating the effect wind chill can have on the temperature in a particular location.

In essence, if it isn’t windy, the location you are in will feel much like the actual temperature that is present. For example if the thermometer says it is 10 degrees Celsius, that is what it will feel like. However, if it is windy, it will feel much colder than that – hence the wind chill factor. This basically relates to how the air temperature feels when it hits your skin.

As you might guess, the direction the wind is coming from can also influence the significance of the wind chill factor. For example, if the wind is coming from the north it comes from colder countries – hence it will bring much colder air with it. If the wind comes from the south, it reaches us from warmer Mediterranean countries, and so it will feel warmer.

As you can see, the wind chill factor therefore has a significant bearing on how cold or warm it might feel – regardless of what the actual temperature is. Therefore, during the winter months you might want to keep a close eye on where the wind is coming from (if it happens to be windy) and how much it might affect the wind chill factor. The more you become familiar with this, the easier it is to work out what you should be wearing on any particular day. If you only go by the actual temperature, you might get a shock when you step out of your front door and feel what it is actually like!