It is normal for the processor to reach 65-70°C while the processor does not exceed Tjunction limit (105°C). Of course fan speed control is required to achieve optimal thermal performance; such cooling solution is provided in this case by the computer manufacturer.
So, the processor is not yet exceeding Tjunction but since this system has been used for some time, I recommend you checking that the fan vents are not obstructed and perhaps you can also get more information regarding what is considered to be normal fan speeds for this model; dust may accumulate over time.