98 GT, condensation under passenger side dash

Hello,

I have a 98 GT. Today I took it out for a spin since it has been sitting for a week or so. Today has been very hot and somewhat humid. I turned the AC to max fan speed and to the coolest temperature. It was blasting cold air as usual but this time it was not cooling the car as much as other times. I was still sweating even though it was blowing cold air.
Upon arrival and turning the car off, I decided to check the passenger side carpet and it had some drops of water on it, barely noticeable. I also noticed that there was condensation under the passenger side dash, mostly on the black housing (blower motor, I assume?). Tested the liquid and it was indeed water condensation and not coolant. It did not have any color or smell. Most of the condensation was on the black housing and not on the carpet.
What could possibly be the cause? I am not that familiar with the HVAC system. The AC compressor and the orifice tube as well as the AC lines under the hood have been replaced a couple of years ago.
Can it be the heater core?

Any suggestions are welcome. Thanks!

Thanks for the information. Any idea on how to get access to the AC drain line? Is it accessible from outside the car (under the car or from the engine bay) or can it only be accessed from inside the car?