Wind Chill Factor

Simple air temperature is not a reliable indicator of how we may feel outdoors. Other weather elements such as humidity, sunshine and wind speed all influence the "real" temperature. How do you measure wind speed without an instrument? Roughly, a wind speed up to 12 mph puts leaves in motion and can just be felt on the face, 13-24 mph moves small branches, raises dust, etc., 25 -30 mph makes wires whistle and moves large branches, 30 - 40 mph makes whole trees move and is difficult to walk against.

This chart shows you must never underestimate the effect of the wind on outside temperatures. Obviously, winds also have relative effects on inside temperatures.

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