I believe in the need for precise language. Comes from a lifetime as a Practicing Logician.
Therefore I will try and use this terminology from now on.
Global Temperature is a 4D Temperature Field.
It is discretely sampled by both point (thermometer) and volume (satellite) instruments with varying methodologies, time windows, area coverage and data sampling lengths.
There exist multiple strategies to go from the sampled data to the actual underlying 4D Temperature Field, all of which will have error bands (and possibly some assumptions) which are often not stated.