Environmental Temperature / Wind Stress Calculator

 Temperature (F) => Relative Humidity (RH) => % Must enter RH or DPT. (leave unknown blank) Dew Point Temperature(DPT) => Wind Speed (V) => Reset Heat Index (HI) => 0.00 Emergency conditions exist when greater than 100 during the day with night values remaining above 75. Temp Humidity Index (THI) => 0.00 Emergency conditions exist when greater than 84 during the day with night values remaining above 70. Temperature Wind Chill (TWC) => 0.00 Predicts chill factor when temperatures are below 91 and wind speed is greater than 4 mph.  Page created by
Dee Griffin and Scott Brogden (Hastings College)

Formulas Used:
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Heat Index (HI), or apparent temperature (ATI) =

HI = -42.379 + 2.04901523*F + 10.14333127*RH -
0.22475541*F*(RH) - 0.00683783*F^2- 0.05481717*RH^2
+ 0.00122874*F^2*RH + 0.00085282*F*RH^2
- 0.00000199*F^2*RH^2

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Temperature Humidity Index (THI) =

THI = F-(0.55-(0.55*(RH/100)))*(F-58)

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Temperature Wind Chill (TWC) =

TWC = 91.4-((91.4-F)*(.478+(.301*SQRT(V))-.02*V))
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Relative Humidity (RH) =

RH = (6.11*10^(7.5*(5/9*(dpt-32))/(237.7+(5/9*(dpt-32))))) /
(6.11*10^(7.5*(5/9*(f-32))/(237.7+(5/9*(f-32)))))*100 © 2003 University of Nebraska - GPVEC, All Rights Reserved Back to GPVEC Home