Scientific American calls bullshit on wind chill:
[I]f the air temperature is, say, 15 degrees F, and a 20–mile per hour wind makes the wind chill –2 degrees F, would the temperature of your exposed skin drop to that temperature?
No. Your skin temperature cannot drop below the actual air temperature. The coldest your uncovered face could get would be 15 degrees F whether the wind is calm or howling at 40 mph….
Try an experiment: Put two thermometers outside, one in the wind and one shielded from it. When you return they will read the same. Or just ask yourself a simple question: If you are driving your car at 20 mph and you read the dashboard thermometer, then speed up to 60 mph, does the temperature drop? No. Because the air temperature has not changed. There is no wind chill for your car—even if you have given your vehicle a human name.
Wind chill is an artificial construct that makes temperatures sound worse than they are. A parallel set of fake numbers makes summer temperatures sound worse than they are. Both serve the interests of broadcasters who seek to exploit public fears about their personal safety by fanning them with constant hype and faked data like “wind chill.”