I'm new here.
Please take this view with caution.
I fixed this:
/ / float factor = 0.00256;
float factor = 0.0265;
Doc ATMEL= The VT output voltage linearly varies with a temperature slope dVT/dT = 2.65 mV/°C.
And added that, as previously stated,
void loop () {
temperatur ();
delay (1);