Are these normal temperatures?

Totally normal if on the low side. If your CPU is less than 15% idle, I expect you to get to 85 C internal for CPU proximity and higher for all the on die thermocouples. Running just unde 100 C is how the silicon is designed to operate at max thermal generation and high sustained load.

Also, if you use the command line tool to check temperatures or thermal load once every 15 minutes instead of having graphs checking every second you may find your CPU runs much cooler. After all, having those graphs update live in real time prevents the CPU from sleeping.

 pmset -g thermlog

Lots of people are surprised or at least concerned by temps:

• Are these temperatures alright?
• CPU Die temperatures reaches 90° C, is that normal?
• Is it normal for a 27" iMac to have CPU core temperatures around 95C under 100% CPU load?
• Retina MacBook Pro running very hot?

From an engineering standpoint, the MacBook Pro and the iMac in the Mac Pro and iMac Pro all have the same power envelope design and push their CPU to 100 C when the work is available. Once the CPU is at Max normal operating load then the kernel task begins to idle potential work so as not to exceed the final design for the processor.

Another solution I have found for this in other forums, is to clean out the dust and accumulated crud from your PowerBook motherboard and internal fan. This improves the cooling efficiency. Over time the Mac gets full of dust and can't cool so well.

This should be done very carefully, there are a bunch of YouTube videos about this. You also need to buy a special screwdriver. This is called a 1.2 mm pentalobe, there are lots of these on eBay for a few bucks. You need one of these to remove the back because Apple use a special kind of screw that no-one else in the world uses, specifically to prevent you from doing anything to your PowerBook yourself.

Do not do this unless you are comfortable with this kind of hardware task.

From the searches I've done, apparently this will not void your warranty, but if you are worried about this, ask your iStore.

This is in addition to using the fix of using right hand ports as described above, which clearly solves the problem.

It doesn't apply to newer laptops unless they have been used in a very dusty environment.