Air Temperature and Human Comfort - The Wind Chill Index

• Often on cooler days when the wind is blowing, the air temperature "feels" cooler than it actually is.

• Why?  ANSWER

• The "Wind Chill Index" has been devised (and recently revised) to account for this effect.

• The formula for calculating the Wind-chill equivalent temperature is:

Wind Chill Temperature (ºF) = 35.74 + 0.6215T – 35.75(V^0.16) + 0.4275T(V^0.16)

where T is the air temperature and V is the wind speed in miles per hour.

• In metric units:

Wind Chill Temperature (ºC) = 13.12 + 0.6215T – 11.37(V^0.16) + 0.3965T(V^0.16)

where T is the air temperature and V is the wind speed in km per hour.