found this.

enjoy

Wet-bulb globe temperature (in Fahrenheit) is calculated with the following equation:

WBGT = (0.7 * Tw) + (0.2 * Tg) + (0.1 * T)

In this formula, there are three important variables to note:

T = Temperature in Celsius

Tg = Globe Thermometer Temperature (in Celsius) this is measured by a thermometer placed in a special black globe to estimate solar radiation without the effects of the light itself

Tw = Wet-bulb Temperature (in Celsius)

The wet-bulb temperature is the lowest possible temperature that air can be cooled down to by the evaporation of water alone, given constant pressure.

This is represented by a rather complex formula:

Tw = T * arctan[0.151977 * (rh% + 8.313659)^(1/2)] + arctan(T + rh%) arctan(rh% 1.676331) + 0.00391838 *(rh%)^(3/2) * arctan(0.023101 * rh%) 4.686035

Here, T is the temperature in celsius and rh represents the relative humidity.

With this final calculation, you can calculate WBGT completely.

it says at

https://perryweather.com/2020/04/01/what-is-wbgt-and-how-do-you-calculate-it/ I guess the black globe thermo replaces sun angle, cloud cover parameters...

But, for me, this is "Too Much Information"...