2012 Yukon Denali

I'm not sure about the ac but as long as you're under 220 degrees you're still in the safe zone although borderline. Best thing to do would be to make sure that none of the brakes are hanging up as that will cause the motor to work harder which equates into more heat. Other than that it probably wouldn't hurt to service your cooling system with a coolant flush and a new thermostat/gasket

Thank you I forgot to mention it's also if im getting on freeway accelerating faster then my normal gradual merging so either way it can go to the next line after 210, not sure what temp that is and I don't know if it's only because of 100° weather it normal sits at 210 middle line.

Here is picture of what looks like over heating

Have you checked the coolant level? If its a little low it can cause that as can the fins of the radiator being clogged by bugs/dirt or if there's alot that are bent, airflow must be able to move through the rad to cool