WBGT Calculators

The Wet-Bulb Globe Temperature (WBGT) is a way to measure the heat stress on a body. 

WBGT takes into account: 

 1. temperature 2. humidity 3. wind speed 4. the intensity of the sunlight (i.e. sun angle and degree of cloud cover) 

 The OSHA calculator estimates outdoor wet bulb globe temperature (WBGT) from standard meteorological inputs. It uses the Kasten-Czeplak algorithm to estimate the clear sky solar irradiance (Sandia, 2012). 

 It then estimates WBGT via the heat and mass transfer algorithm of Liljegren et al. (2008). 

 This product includes software produced by UChicago Argonne, LLC under Contract No. DE-AC02-06CH11357 with the Department of Energy. 

 See copyright notice at the bottom of the web page: https://www.osha.gov/SLTC/heatstress/wbgt_calculator.html 

 The University of North Carolina (UNC) also has a WBGT calculator and more details about the measurement and its meaning online at: https://convergence.unc.edu/tools/wbgt/. (Click on "What is WBGT"). One can also download a flyer about WGBT on the website.

The figure above is from the UNC website.

Here's a key fact about WBGT from the UNC website: 

 How does WBGT differ from Heat Index? 

 Like the heat index, the WBGT takes into account the temperature and humidity of the air. It also considers the effects of solar radiation (e.g. heat stress is greater in the sun) and the wind speed (e.g. heat stress much greater when the winds are not blowing).