This temperature is ok, you have a condition known as heat soak, basically when you are stationary you have very little air passing through the radiator and through the engine bay to cool everything, only that supplied by the fan. When you move natural airflow passes through the radiator due to the movement of your vehicle, this cools it naturally.
When you stop the same amount of heat is present, having less airflow means this heat is harder to dissipate, temperatures rise slightly and as the heat is dissipated, it slowly drops down to normal.

If you are concerned drain the coolant and fill with water, run the engine until it is hot and drain it to remove any debris in the cooling system, refill and add a coolant system cleaner. Follow its instructions and thoroughly flush the system, replace the thermostat as a precaution.
One tip is to open all the windows, sunroof, etc and when you stop put the heater on maximum heat and the fan on full blast, the heater radiator will remove quite a lot of heat.