Sounds like a stupidly easy question to find out with a quick internet search, but it’s not.
I don’t want to know the average surface temperature, or the average ocean surface water temperature, or read another article about climate change.
But that’s all I found in the past hour.
I’d like to know the average temperature of all molecules that comprise earth, or a best guess scientific estimate.
I think the median average temperature is around 2,200°C.
The Earth has a radius of 6,371km, giving a volume of 1.08e13km^3.
A sphere of half this volume would have a radius of 5,057km. Within the Earth, this sphere would sit at a depth of 6,371 - 5,057 = 1,314km.
From this chart, the temperature at that depth is around 2,200°C, so half the volume of the Earth has a temperature above that, and half a temperature below it.
The problem with that is the temperature inside that sphere gets over 4000 degrees above that value and the temperature outside that sphere only gets to around 2000 degrees below it.
Edit: Just realized you said the median, you may be right.