thanks for sharing this. but I’m not sure is this the right one. I have compared the apparent temperature given by dark sky vs the result calculated at https://www.calculator.net/heat-index-calculator.html using the temperature and humidity value from dark sky are quite consistent.

I was just rereading this thread after I came across it again. I just realized we had very different goals in mind.

The heat index calculation you’re using is, in fact, the correct calculation for outdoor “feels like” temperatures. My goal was to calculate a “feels like” temperature for the indoors, which is a very different calculation–note the NOAA formula is only accurate down to 80 degrees F, which would definitely be outside my comfort zone for an indoor temperature.

My usage is primarly for the purpose of tweaking indoor thermostat settings based on a “feels like” temperature rather than an absolute temperature.

Hopefully, that clarifies the use-case and reasoning behind the different formula.

I’m a bit confused with the above calculations, as the UK Meterology Office describes outdoor ‘Feels Like’ temperature as a measurement of temp/humidity/windspeed at a height of 5ft. Unless I’m missing something I don’t see windspeed integrated in those calcs. If I find the calculation for this missing piece of info, I’ll post it here.

Are you still using this formula for indoor? How has it worked for you?
I’m looking into implementing something like that for my home and I think what you wanted is exactly what I want to do.
Could you tell me if you have noticed a difference by using the feeling temperature compared to the real temp?

There’s generally not a vast difference between the measured temperature and the feels-like temperature. For example, right now there’s only a one-degree difference between the feels-like temperature upstairs and the actual temperature (69.8 vs. 68.8) and that’s with 66% humidity.

I was going to try to look at a historical graph and discovered that history doesn’t record derived values, unfortunately. Otherwise, I might have been able to see how much of a delta I saw between the two.

If you’re interested in picking up a 1-2 degree difference, it might be useful; otherwise, it’s more of a novelty, I think. To answer your question more directly, the only place I leveraged the feels-like temperature is in determining whether to switch over between A/C and Heat. Otherwise, my house uses the thermostat temperature as you would normally.

They all follow nearly the exact same pattern but have significant offsets. Not to criticize anyone’s work, but IMO “SenxorX Real Feel” felt the closest to my expectation of temperature experience.

Hi,
Perhaps heat index and apparent temperature are relatively different concepts with different scope of application ?..

First about Heat Index:
Heat Index shows how much hotter the air seems to be than the ambient dry-bulb temperature due to the influence of humidity.
I found that the formula of the multiple regression analysis conducted by Lans P. Rothfusz is limited by temperature >~27C. Accordingly, for lower temperatures, the result may have large discrepancies relative to the original tables by Steadman. Although a simplified expression ( HI = 0.5 * {T + 61.0 + [(T-68.0)1.2] + (RH0.094)}) is given to circumvent this limitation.

On the other hand, the Apparent temperature has a wider range of acceptable values of dry-bulb temperature values (>20C).

Therefore, it may make sense to combine formulas. However, it should be borne in mind that the heat index / apparent temperature graphs intersect at different temperatures.