2002 Other Jeep Models Engine runs slightly hot at high RPM'

I have an '02 Jeep Grand Cherokee that is equipped with a hydraulic fan. I recently performed a complete flush and fill of the coolant and replaced the thermostat while I was at it. Problem is, my Jeep runs at normal temps during highway driving or mixed highway/city, but at high RPMs (prolonged stop & go, or long stretches of inclines), the engine temp creeps past 210* (which is the middle of the gauge) but does not get close to overheating. If I go back to regular driving, it goes back down to normal. Not sure if this is normal, or what the problem could be.