Windchill

For many of us, the weather is rather inclement at the moment. In many parts of Europe snowfall has given a very wintry vista and the wind has also started to get up. The combination of low temperatures and wind has given us a new addition to our vocabulary in the past thirty odd years – Windchill.
What is windchill? Very simply, it is the cooling effect of wind – we notice it on a summer’s day when, despite temperatures in the high 20s, the breeze makes for a slightly more amenable feeling. In the winter we notice it even more – it is the difference between a crisp, windless morning with the temperature around -5˚C and the equally crisp but windy morning with the temperature barely below zero. Despite its higher temperature, the latter is decidedly less pleasant, feeling as if the temperature is closer to -10˚C.
Which is in effect what we are feeling. The wind is drawing the heat off the skin giving the effect of a lower temperature than measured (in fact, air temperature is measured in a Stevenson Screen where the effects of sun and wind are minimized).
There are various tables for actually determining windchill – some don’t go above 4˚C because above that temperature, the dangers of windchill are, to all intents and purposes, nil, although it does not mean the effects aren’t felt. The purpose of this article is not to be able to calculate windchill – there are enough references to be found by Googling – rather to look at the effects in horses.
We have the tendency to look at our pets and make human considerations about their wellbeing. We raise food bowls, we provide soft beds with blankets/straw, we put coats on them, give them clean tapwater etc. And yet, they prefer to drink out of dirty puddles, eat from the ground, roll in the snow and sleep on the hard floor!
So, what about horses and windchill? Well, as far as I know, there has been no direct research into the subject. Nevertheless, it can be very easily concluded that the “feels like” temperatures we are given, cannot be applied to horses. Why not? Simply because the “feels like” temperatures are derived from windchill data and that is based upon temperature loss on exposed skin. And specifically, human skin. Although basically similar, a horse has a much thicker insulating skin than a human and then obviously a much denser coating of hair. The skin alone will make quite a difference to the “feels like” temperature – with the hair on top, the difference is vast.
So next time you think it is too cold for your horse, think again… It probably isn’t!