WBGT is a measure of the heat stress in direct sunlight, which takes into account: temperature, humidity, wind speed, sun angle, and cloud cover (solar radiation). This differs from the heat index, which takes into consideration temperature and humidity and is calculated for shady areas. For more background info on WBGT

WBGT is calculated as the weighted sum of natural wet bulb temperature (Tnwb), globe temperature (Tg), and dry bulb/ambient temperature (Ta): WBGT = 0.7Tnwb + 0.2Tg + 0.1Ta.

This Calculator is used to estimate the WBGT of a user-provided location. It uses weather data collected by OpenWeather. The weather data, in addition to the user-provided location, is then entered into a formula that calculates the current WBGT for the user-provided location.

The WBGT is used to determine when a heat exposure hazard exists. The higher the WBGT, the more likely it is that a person may suffer a heat-related illness.

You can schedule an alert for a location of your choice. We will send you an email when your alert location reaches a certain WBGT and provide you with the estimated WBGT. To get alerts, just click the login button, sign in to Auth0 (this is a free authentication service that will protect your password), and you will be navigated to the dashboard page. There you can set a WBGT or check previous alerts you have received.

This calculator is based on the Kasten-Czeplak algorithm to estimate the clear sky solar irradiance (Sandia, 2012). Please visit the About page for a detailed explanation of how the calculator works, its limitations, and its accuracy.