I wonder if the temperatures on my non-retina Macbook Pro 13 Mid-2012 normal. I browse using Firefox. I tried using Safari but no noticable difference. CPU load is low. OS X version 10.8.5.
Yes - everything looks normal. Battery and charger are good. HDD and GPU are fine. CPU and cores running cool.
T-JUNCTION of the processor is 105 °C for the i5 (Intel® Core™ i5-3210M Processor) and the i7 (Intel® Core™ i7-3520M Processor ). The Junction Temperature is the maximum temperature allowed at the processor die.
The temperature shown in your screenshot is ~30 degrees Celsius lower than the max. allowed. So I would expect it to be still completely normal.
Surfing with a Intel® Core™ i7-2720QM Processor (T-JUNCTION 100 °C) in a MacBook Pro with a CPU-load of 15% and an environmental temperature of ~10 °C I get an average of about 60 °C.