I'm still becoming familiar with my 6700K rig, but that does sound about right, depending on what load you're putting on the system.
The Skylake is manufactured following the pattern that arose with Ivy Bridge followed by Haswell: no more use of Indium solder for the consumer chips between the heat-spreader and the processor die. Skylake uses a polymer thermal interface material.
By contrast, you can order a processor from Silicon Lottery online and pay $50 to have it de-lidded and then re-lidded with Liquid Ultra. It will buy you between 8C and 18C improvement in temperatures. At the same clock-speed and voltage, my chip is about 5C cooler than a retail-box CPU without the re-lid in a test-bed featuring an external dual-fan EXOS water cooler. I'm using a ThermalRight LG Macho heatpipe cooler.
I'm not suggesting that you do this, although Silly-Lotts will perform the $50 service if you mail them your chip. Otherwise, those are the temperatures you can probably expect under stock load conditions, and they're going to increase if you overclock.
What stress test are you using to generate those temperatures? That will give us a better idea of your expectations or an assessment of your temperature results. I can revise my comment with that information.