<p><a href="https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2021EF002334" rel="nofollow noreferrer"><em>Explicit Calculations of Wet-Bulb Globe Temperature Compared With Approximations and Why It Matters for Labor Productivity</em></a> might help explain what's going on.</p>
<p>Liljegren's method appears to be calculation intense. It involves three equations, the two main ones are for T<sub>w</sub> &amp; T<sub>g</sub>, equations 3 &amp; 5. The equations needs to be solved by iteration.</p>
<p><a href="https://i.sstatic.net/MWEhg.png" rel="nofollow noreferrer"><img src="https://i.sstatic.net/MWEhg.png" alt="enter image description here" /></a>  <span class="math-container">$..............(3)$</span></p>
<p><a href="https://i.sstatic.net/ULNEw.png" rel="nofollow noreferrer"><img src="https://i.sstatic.net/ULNEw.png" alt="enter image description here" /></a>  <span class="math-container">$..............(4)$</span></p>
<p><a href="https://i.sstatic.net/TUwdC.png" rel="nofollow noreferrer"><img src="https://i.sstatic.net/TUwdC.png" alt="enter image description here" /></a>  <span class="math-container">$..............(5)$</span></p>
<p>By ignoring direct sunlight &amp; wind speed, the web page you link to is simplifying things &amp; producing an approximation; something similar to calculating sW BGT, equation 1.</p>
<p><a href="https://i.sstatic.net/aOCIK.png" rel="nofollow noreferrer"><img src="https://i.sstatic.net/aOCIK.png" alt="enter image description here" /></a>    <span class="math-container">$.............(1)$</span></p>

CC BY-SA 4.0
2023-05-31T08:26:17.777Z
2023-05-31T08:26:17.777Z
Fred
<p>Greetings fellow scholars,</p>
<p>I'm trying to answer the question above because I've come across WBGT calculators like this one (<a href="https://www.climatechip.org/heat-stress-index-calculation" rel="nofollow noreferrer">https://www.climatechip.org/heat-stress-index-calculation</a>) and I don't understand how the answers are derived using the Liljegren method without more variables (other than temperature, humidity and assumptions on direct sunlight and wind speed).</p>
<p>The paper, <a href="https://doi.org/10.1080/15459620802310770" rel="nofollow noreferrer">Liljegren et al. (2008)</a>, method is pay walled. I've tried digging into the code of projects like <a href="https://rdrr.io/github/anacv/HeatStress/src/R/wbgt.Liljegren.R" rel="nofollow noreferrer">this one</a> but they're using more variables.</p>
<p>If anyone can give an explanation of what's going on with these calculators or point me to a code repo/paper where I can try learn more, please do.</p>

<temperature><measurements><humidity><data-analysis>
How to calculate wet bulb globe temperature (WBGT) using only temperature and humidity?
Dt23
# How to calculate wet bulb globe temperature (WBGT) using only temperature and humidity?

(Asked by: username_0 on 2023-05-30)

Greetings fellow scholars,

I'm trying to answer the question above because I've come across WBGT calculators like this one (<https://www.climatechip.org/heat-stress-index-calculation>) and I don't understand how the answers are derived using the Liljegren method without more variables (other than temperature, humidity and assumptions on direct sunlight and wind speed).

The paper, [Liljegren et al. (2008)](https://doi.org/10.1080/15459620802310770), method is pay walled. I've tried digging into the code of projects like [this one](https://rdrr.io/github/anacv/HeatStress/src/R/wbgt.Liljegren.R) but they're using more variables.

If anyone can give an explanation of what's going on with these calculators or point me to a code repo/paper where I can try learn more, please do.

**Tags:** temperature, measurements, humidity, data-analysis


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## 1 answers

### Answer by username_1 on 2023-05-31. Score: 2 | Accepted answer

[*Explicit Calculations of Wet-Bulb Globe Temperature Compared With Approximations and Why It Matters for Labor Productivity*](https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2021EF002334) might help explain what's going on.

Liljegren's method appears to be calculation intense. It involves three equations, the two main ones are for Tw & Tg, equations 3 & 5. The equations needs to be solved by iteration.

[![enter image description here](https://i.sstatic.net/MWEhg.png)](https://i.sstatic.net/MWEhg.png) $..............(3)$

[![enter image description here](https://i.sstatic.net/ULNEw.png)](https://i.sstatic.net/ULNEw.png) $..............(4)$

[![enter image description here](https://i.sstatic.net/TUwdC.png)](https://i.sstatic.net/TUwdC.png) $..............(5)$

By ignoring direct sunlight & wind speed, the web page you link to is simplifying things & producing an approximation; something similar to calculating sW BGT, equation 1.

[![enter image description here](https://i.sstatic.net/aOCIK.png)](https://i.sstatic.net/aOCIK.png) $.............(1)$


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