Ac works fine when compressor worksbut the problem

Check low side pressure or try bypassing low pressure switch with a paper clip in the connector. If pressure is good but bypass works, you need a new pressure switch. If pressure is low, charge the system. If pressure and presxure switch are good, please get back to me and I'll do some research.

excessive pressure on the high side from blockages
condenser fan not operational
loose wire to the compressor
problem ac relay
problem thermostat
problem climate control module
take it to an accredited ac specialist shop and have the system checked and properly diagnosed

Have an AC repair shop hook up a set of AC pressure gauges while this is happening to see what is going on. You could have a defective AC compressor or a low refrigerant charge in the system. And as to the hot weather causing it to act up that would be normal, the AC would cool fine the cooler the outside air is, problems like worn out compressors and low system refrigerant charge levels would only show there ugly head in hot weather conditions. Also make sure the cooling fans fo rthe AC and engine are working properly. Good luck with this.

if the fan slowly comes up to speed check the connections on the resister they over heat and melt then check the fan motor itself

time for a new compressor. It's a magnetically controlled belt driven compressor. If it isn't clutching anymore, it's dead. pretty soon it'll start squealing or making other funky noises if it isn't completely dead yet, then soon you'll press the "ac" button and nothing will happen.

I have the same problem right now, and from what I can figure, it looks like an intermittent thermal protector switch on top of the AC compressor. My 2003 Civic air conditioning works fine for 20 minutes or so and then stops working. If this switch is faulty, the compressor clutch won't engage and you won`t get cold air. I will get it replaced soon, but it seems like the access is not easy.

Check if the compressor is working.
looks like there is a problem with compressor , hence working intermittently.

two things you may try, relocate ambient sensor to colder place, remove it from front bumper, and connect the two wires on refregerant temp sensor located @ rear of compressor, be carefull and observe your a/c system after doing this

The problem is most likely the AC compressor clutch connector. It is a one pin connector. Located under the hood, near the clutch of the AC compressor. Clean this connector, make sure there is a good connection. I had the same problem and had to fix it myself. Works fine ever since.

check your air gap on the compressor pulley where the clutch and pulley meet. you should be able to fit a postcard in between it. if thats good then check your tensioner. there should be lines on it to tell if its wore out