There's no guage reading on the Thermostat, so it is difficult to determine what the actual temperature is in the cooling system.
That said, the guage does show a very small red area at the top so it would appear to me, that anywhere but the red area would be a normal operating temperature.

When we were getting the hot humid blast of air, over the last two weeks, I was noticing my guage creeping up towards the 3/4 mark as well.
This was only while the vehicle was stopped.

Once on the move the radiator cooled things off relatively fast. the needle crept back down, and hovered just above the center.

Now with the cool weather the rain brought, everything is back to sitting in the middle.