The TCase temperature for the Intel® Core™ i5-3570 Processor is listed as 67.4 °C. The TCase is a point of reference in order to understand what could be expected as per normal processor temperature.
Anything from the Tcase and below will be the expected temperature of the processor in normal use, anything that doesn't stress out the processor (watching movies, burning CDs, browsing the internet, creating documents, etc.) When the processor is stressed out, meaning that you are running heavy processor applications that take control of the CPU, the temperature can go beyond the Tcase. The cooling fan is in charge to keep that temperature there.
In your case it is barely reaching TCase, which is good.