while driving ur car the air is entering ur engine and the temp will be fine now if the temp if incresing (not too fast), while stopping thats means 2 things happen
1. the big fan clutch is not working
2. the electric fan is not working and comes with 2 speed (hight and low)
now start ur car and once the temp if half the big fan shuld work push the accelerator and u should feel big amount of air comes from the fan dont try to touch another noise of air should happen.
if the big fan is working that means electric fan not working turn on the a/c and check it if its running the fan is fine , now there is small thermostat on the side of radiator maybe its damaged of fan cutout if burn or fan fuse.
and maybe ur radiator having some air when ur car is cold open the radiator cap and also open the air removal screw start ur engine and start to fill the radiator you will found some bubble comes from the air removal screw once bubbles disapper close the screw and the cap.
some times if radiator is not full electric fan will not start coz the small thermostat will not measure the temp ...... have good day