Originally Posted by
Hypno Toad
This week's Wedge Issue: Wind Chill Factor is Pointless
No, it isn’t. More on that later.
Wind chill factor is great for The Weather Channel to hype cold temps and create drama, but it has very little effect when your riding a bike ... unless you're a nudist.
Yes, it is an overhyped concept but it
does have an effect on you while riding a bike…or walking around…or sitting around…in the cold. More later.
Here's the challenge for those that want to argue for wind chill: With the air temp is 35F/1.5C and the wind is 20 mph/32kph making the wind chill 24F/-5C, you put a glass of tap water on the patio table ... will the water in that glass freeze?
SPOILER ALERT! No, the water will not freeze until the air temp is below 32F/0C.
Just because you don’t understand physical chemistry and use the wrong analogy, doesn’t mean that “wind chill” isn’t a thing. “Wind chill” doesn’t have an effect on inanimate objects because “wind chill” is about perception. In a wind, the water in the glass will cool and it may even cool below the freezing point, depending on the conditions. But you are correct that it won’t freeze due to evaporative cooling under the conditions you lay out. However, the original work on wind chill did use the method you suggest.
For rides when it's cold and windy, simply include a wind blocking layer and dress the same as you would for the air temp. Wind chill is about the lose of heat from exposed skin, and I don't know anybody going out with exposed skin when temps are cold enough to consider wind chill.
For reference, yesterday I rode for 90+ minutes with air temp at 0F/ and 6 mph winds, making the wind chill factor -12F/-25C. I dressed for the conditions, and a wind block layer is part of my winter kit any time the temps are below 45F/8C, regardless of the wind speeds (or wind chill factor) because riding a bike is creating a constant 10-20 mph (16-32 kpm) wind.
Yes, you dress for the conditions. But what tells you that you need to increase your wind blocking layer (or to use one in the first place)? You may not use the “wind chill factor” to calculate the amount of clothing you need but you use the concept to reduce the chilling effect of that wind. “Wind chill” is a thing. Yes, it’s over used…like “black ice”…but it is a thing and is helpful to know at least something about before venturing out into the cold and wind.