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.
The mean temperature of the earth is 59°(15°C). This is from NASA Science Solar System Temperatures. I don’t know if this answers your question but I gave it a shot.
This seems more like an average surface temperature than an average temperature of all the molecules comprising earth