Considering simple matters as the ambient temp, frequency and cooling that I have, I'm pretty confident of my assumptions.

coretemp 0.95 reports the following:
core0: 31°C (delta 54°C)
core1: 28°C (delta 57°C)
read interval 1000ms

My ambient is 21°C measured by analogic quality thermometer. The assumed TCC is 85° (by coretemp) and it seems accurate to me.