A/c gets hot at idle

My 2013 corolla le tends to stop sending cold air into the cabin when I come to a stop. It will instead give me muggy warm air that is less than helpful in Florida weather. Any suggestions as to what could be my problem?
I think it is normal for the air to be less cold when at a standstill, engine is at lower RPM thus making the compressor not turn as fast, however if the air is actually warm I would start by checking the state of the A/C gas charge, you may be low.