During high temperatures (80+degrees) my AC doesn't work. I hear the AC compressor turn on for like 5 seconds and then shuts off and then just keeps happening for couple mins and never turns back on until later. The AC works fine, when it's around 80 degrees and lower though. Could it be my AC compressor or what is it?

 

It's not the compressor if it works at all. Check the pressure. The pressure of the system increases with temperature. There's a shutoff valve that shuts down the system if the pressure gets too high.

 

Agreed although your car isn't really that old it may still need an A/C recharge.

 

if it needs a recharge you should check for a leak.