I would bet money that it is your CPU temp. 4.52 on air when it is going to be under load is pretty high. Those temps are what you are likely to see.
But look at the max temp for cpu, its 49c how could it be that? I dont understand
Good question and that isn't one I can explain. I have used HWMonitor for quite some time though and the temps on that have been correct at least for me. Mine actually lists the reading as CPU though not tmpin2. Maybe the tmpin2 isnt the CPU temp and if that is the case, I am not sure what it is.