Electrically driven A/C has been a long time coming. The problem is that cars are a 12v system, and that isn't nearly enough voltage to run a compressor effectively, or at all. The least voltage I'm aware of that you can run an air conditioner with is 110V/20A and that is your typical window A/C unit that is 12,000 BTUs or less. Maybe a couple thousand more BTUs with more efficient compressors and motors, but that is about where a 110v A/C system tops out. Then it is up to 220V/30A units to go beyond that. In other words, effective A/C requires high(er) voltages than we have seen in cars prior to now. And that is why belt driven A/C in cars is defacto standard.

To answer your question directly, where I live summers can get really hot and dry. We had at least a couple July and August days over 100. The Prius A/C works beautifully. I admit, I avoid parking the car in direct sunlight, but when I have to the A/C system is able to pull down the car to livable temps very quickly. And if the drive is long enough it will cool the car to your temp set point and throttle back the fan speed.

The electric A/C system is fully automatic and as such you set the temp and forget it. It manages air source (recirc/fresh) fan speed, outlet vents used etc. I have found that its logic is pretty good. You can override any of the automatic items, however the system just doesn't seem to run as good as if you let it do its own thing. On top of that, unlike belt A/C where the compressor speed varies based upon crank shaft speed, and there are basically only 2 conditions of operation, on or off; the Prius electric A/C compressor is variable speed and will actually lower speed when less cooing demand is indicated by the climate control system. I find very little impact in running the A/C on fuel economy in the summer. I have much greater FE decline in fall and winter than in the summer with A/C on. On top of that, the HV battery uses cabin air for battery cooling. It is important to have a comfortable interior for yourself and the battery. I have advised others that if you are sweating in your car, your battery is doing the same, and reducing your overall efficiency. So, it is advantageous to run the A/C, if not for your sake, for the car's.

I think you will find the Prius A/C system up to any challenge.

It has been said:
Hybrid drivers come in 3 flavors, greenie, techie and cheapie. Pick any 2.
2005 Prius, Melinium Silver over gray, package 5 (AI)