Mid 60's under load is fine for any CPU.
But for comparison: my i5-6600K with
Arctic Freezer I32 and 2x
Corsair ML120 Pro LED fans (in push-pull) maxes out at 55°C (during Cinebench R15). While my CPU idles around 26°C. Then again, i have 6x 140mm and 1x 120mm high-end case fans in my PC to cool it all. My Skylake build, full specs with pics in my sig.
So, unless you go with aftermarket cooler with better cooling capacity, including better overall cooling for your PC, you won't be seeing any lower temps out of your CPU under load.