All you need to install is
At first time you install ‘hddtemp’ , the program will ask your decision to run automatically a ‘hddtemp’ very time PC booting: if not, you need to run it your self by command .. >
> hddtemp -d SATA:/dev/sda
After that, only you add an applet to task bar. You’ll see real-time temperature monitoring not only from harddisk but also from cpu and etc,.