I own a 2010 Subaru Forester and my AC isn't cooling very well. Any ideas?

My AC seems to function quietly and normally. The compressor kicks on and off like it should, the low side pressure is normal and the cores are clean. It all seems to work just fine. But, on a hot day (80+), the air being forced out inside just doesn't feel very cool, unless I'm sitting in a shaded place, when it's noticeably cooler (about like it should -normally- be). I starting noticing this difference about a month ago when the temperature started getting near 90 and seems to have gotten slowly worse. I bought the SUV 20 months ago as a Subaru Certified Used Vehicle and it's now out of warranty with 62K miles on it and is otherwise in overall excellent condition. Does anybody have any ideas why it's not blowing snow, well maybe not snow, but COOL air?
Answers
There is a leak in the line or it needs a charge.
23 Telluride SX-P X-Line, 23 Camry XSE
No, I've checked the pressure and it's well within the normal range. The compressor cycles just as it should and all seems well. The air is just not very cool
I don't know exactly how your car is set up, but this could be an issue with the secondary cooling fan not kicking in properly. You might do a scan to see if that type of trouble code pops up. I had the exact same problem on my MINI and it was the secondary fan module--if you can't blow air on the condenser then the refrigerant just stays too warm. The fact that your AC works better in the shade makes me think this could be the issue, possibly.
The cabin (inside) fan blows well on both heat and cool. All speeds seem to works fine. I can't figure it out! I'll likely end up having the system drained & recharged. I had to do the same with my last 01 Forester. I recall now it did the same thing several years ago with no answers. I had most wearing parts replaced, a vacuum pulled and a total recharge.