My power supply fan has suddenly started becoming really noisy and I am wondering if it is affecting my CPU temperature.
I have a desktop with a 6-core CPU. This is what CPU Thermometer shows me:
Is this normal temperature for this load?
Without knowing your ambient temperature, this seems very good to me for an idling processor.
Expect about Ambient + 10C at idle on average
Judging by the fact you have a desktop, this isn't just down to the CPU. Given you might have high powered RAM and GPU these also contribute to the noise your computer makes. Open her up and have a look. Nothing like a bit of good observation to find out what's making the noise.
Depending on your hardware, this may be a better system monitor for your machine: