if youre boiling water, it can be any arbitrary temperature above 100.

That’s not how boiling works. The water heats up to its boiling point where it stops and boils. While boiling the temperature does not increase, it stays exactly at the boiling point. This is called “Latent Heat”, at its boiling point water will absorb heat without increasing in temperature until it has absorbed enough for its phase to change.

There is an exception to this called superheating