What software are you using to monitor this?
 
Can you install this software and recheck the temps?
 
http://www.evga.com/eleet/
 
(make sure you download the version for X99)

Overall CPU and socket temps are usually higher than your individual core temps.  Everything looks fine here.

CPU Package is always around 4-6C hotter than Core Temps.
On my R5E is same.
 
At this moment, right now X99 Micro 2 is nicest motherboard on market.
Definitely, more I look, I'm more and more sorry because I don't have.
OK at least it's not some ultra expensive motherboard. 
She is small but have everything important.
Even 10 SATA Ports, like real Xtreme motherboard for enthusiasts with huge data.
Only one thing should be changed...
EVGA should make little overkill with power section, example 8-10 phases Digital VRM and
to keep EZ Voltage read points and angled 24 pin connector. They could make that for Skylake-X, EVGA X190 Micro.  

I notice over net good part of people who build Z170 configuration are not aware that X99 platform could be build for same price or even lower.
Example average Z170 platform is i7-6700K, some Z170 motherboard 200-250$ and 2x8GB DDR4 arround 100-120$.
Many people decide to go with Hero 8 or similar motherboards, their price is not any more 170-180$, it's about 230$.
i7-5820K cost 380$ but could be find for 300-320$, Micro is 225$ and GSkill 16GB Quad cost 120$, 32GB about 200$.
If someone want to start with rendering and need really strong CPU for work i7-5820K is best chance.
It's completely different scenario than last two models, i7-3820 and i7-4820K...Some people are confused because he have similar name.
But they had 4 cores and i7-5820K is more like i7-3970X and i7-4960X.
Their specifications are same. Same number of cores 6 and same L3 Cache 15MB is most important.
My memory is QVL for Micro 2. I have Dominator Platinum 2666 C15.
Maybe is that kit expensive for someone but GSkill offer cheaper kits with same performance only without light and nice heatsinks.
Who could imagine before 12-18  months that Haswell-X X99 6 core and DDR4 could build for 600$, everything, CPU, motherboard, Memory.
 

I remember on my ex system Z77 everything was same Package was about 5C more and LED on motherboard showed Package Temps.
I clearly remember. 
I don't know X99 have better processors and Z170 is good platform. 
Z170 chipset Gen 3 compensate little lack of PCI-E lanes but L3 Cache and 6 cores can't replace.
Skylake E will be perfect platform, for 2 years about. 
If I find cheaper CPU as i7-5820K I will upgrade, why not. 
But I expect and new socket because that mean more place for improvements and bigger difference than Haswell.
Depend of many factors, default CPU clocks, models, price... Maybe Intel decide to go with one CPU 6 core and two CPU with 8 cores.
Nobody can't give warranty that Intel will set same price and same specification. 
With X79 chipset Intel launch two models with 4 cores probably because smaller number of people was interest only for i7-3930K and i7-3970X.
This year they show with better offer, 6 cores 15MB L3 for almost same price as i7 for Z chipsets and if someone don't use that situation bad for him.  When you keep tham in hand i7-3770K/I7-4790K/i7-6700K are so small compare to i7-5820K like Intel Xeon...
And you know that's CPU inside are 6 cores, memory controller, etc... Not IGPU half of small CPU.
Than customer and can't expect better cooling and good heat transfer, special with paste.
But I have feeling that i7-7930K and i7-7820K could be good overclockers, at least same as Haswell-E. 
OMG when I only think about OC CPU I remember that i7-5960X from 3.0GHz OC on over 4.3GHz and I feel bad because someone bought before me for 500e one. How to miss such nice Processors, for now best Intel, we will see, maybe i7-7960X beat him.
I hope Intel will start with Turbo closer to 4.0GHz to increase single threaded performance of Skylake E on default settings.