Wind chill is the increased cooling affect on warm bodies(warmer than ambient) caused by wind.
More precisely. A warm body loses heat by convection. When you add wind speed, it increases the rate at which that warm body loses heat. The wind
chill factor is the equivalent calm air temperature that it would have to be to lose heat at the same rate as it loses heat in the warmer but windy
Basically, if it is 25F and the wind chill is 10F then the calm air temperature that it would have to be to lose heat as fast as you do in a windy 25F
It only affects objects that are warmer than the ambient. Once the object gets down to ambient, then wind speed doesn’t have an affect any more.
And inanimate object that is already at ambient, will not get any colder than ambient, no mater how fast the wind is blowing.
If memory serves me right, The reference hot body (human skin) temperature for wind chill calculations is around 60F
If the overpass freezes over, then the air temp is below 32F. I don’t care who made your thermometer, it is wrong.
The abundance of mechanical thermometers has always been a constant irritant to me. They have poor accuracy. They have a tendency to stick, or not
move until the temperature changes drastically. And they have a tendency to freeze solid at 32F. They get moisture in them, and when the temp drops
below 32F, the water freezes, and the needle doesn’t move until the temp warms up above 32F.
I always stick with liquid thermometers. The alcohol type, or more preferably, the mercury type. To make sure they are calibrated, put them in a
bucket of ice water. If the temp reads 32F, you are set. If it reads anything else, then break the glue loose that is holding the glass tube and
recalibrate and reglue it.
edit on 26-2-2011 by Mr Tranny because: (no reason given)