AC is blowing hot air when car is not moving in hot weather (above 90)

It could be the evaporator fan. With the engine cold and hood open, start the engine and turn the AC on. The fan behind the radiator should turn on, there may be a delay on that car. If it doesn't come on you probably have a bad fan or maybe a bad fan relay or fuse that blew. It could be low on freon, some ACs do funny stuff when low on charge.

Is the engine running hot?