Is there a live chart available?

I did that too, the tiny fan is pretty much silent at 5V. The HDD has so much surface area it only needs a little air circulation.

When an HDD works continuously it can heat up to above 60 °C if proper air circulation is not allowed, which can cause a very premature failure. In fact, it should be kept under 40 °C to achieve the intended lifespan. Unfortunately, PC cases are usually not great at removing heat from the HDD by default.

As for your drive, it most likely has a temperature sensor so it can be displayed by various utilities.