What Is the Relationship Between Temperature, Magnitude, and Scalar Quantities?

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Temperature is classified as a scalar quantity, which means it can be represented by a single number and does not have a direction. While magnitude is typically defined as non-negative, temperature can indeed take on negative values, such as -30°F. The discussion highlights that the Kelvin scale, which cannot have negative values, is more physically meaningful than the Celsius scale, which is based on subjective human definitions. The distinction between scalar and vector quantities is emphasized, noting that vectors have magnitudes that are always positive. Overall, the conversation clarifies the relationship between temperature, magnitude, and scalar quantities, underscoring the complexities involved.
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Alright, I was reading this thread: https://www.physicsforums.com/showthread.php?t=239733

And I read somewhere that temperature is a scalar quantity with magnitude.
But in the thread above, a poster said that a magnitude is always zero or positive.
But then again... temperature can also be negative.
So, how can temperature be a scalar quantity and have a magnitude if it's -30F?
 
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In general, a scalar is a quantity that can be represented by a single number with units (no direction). It can certainly be negative.

The magnitude of a vector is the length of the vector, which can only be positive.
 
Temperature can only be negative if you use a useless unit of measure, anyway.

You can not have negative kelvins because the kelvin scale makes sense. The celsius scale works, but its values are based on something subjective that humans decided and not something with any real physical meaning.
 

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