That’s not a type. A NaN is a floating point number (of type float). I used numpy because that’s the easiest way to get a NaN.

This is part of the floating point standard.

This was never about None, which is a completely different thing.

NaN is a special floating point value. https://en.wikipedia.org/wiki/IEEE_754

It’s weird but it makes sense why it was chosen to be this way.

They say a picture is worth a thousand words.

It’s not true in a normal programming language. If it is true in yours, you should stop using it immediately.

But when it comes to weather, the boiling point of water is not a meaningful point of reference.

Well, the freezing point of water is very relevant for weather. If I see that the forecast is -1 degC when it was positive before, I know I will have to watch out for ice on roads.

And the boiling point as the other reference point makes complete sense.

Some countries already use it officially too :)

About the only useful thing I see is that 100 Fahrenheit is about body temperature. Yeah, that’s about the only nice thing I can say about Fahrenheit. All temperature scales are arbitrary, but since our environment is full of water, one tied to the phase changes of water around the atmospheric pressure the vast majority of people experience just makes more sense.

I don’t see how your example is ‘funny’. That’s what you expect to get. -5² is -25. (-5)² = 25.