AC compressor not engaging

First world problems, right? AC not working in winter? It was working fine a few days ago (isn't everything that breaks working fine?) No signs of anything bad happening, no squeals, no smells, nothing. I recently moved back to Colorado from being in Vegas, so I'm thinking it didn't like the trip. It is a 2007 frontier with 105k miles.

I can cycle through all the speed settings on the blower just fine. AC light comes on but I can't feel or hear the compressor engage. I checked the fuse under the hood and it was good (10 amp fuse). I checked for code and there's nothing, no pending and no stored codes.

I didn't smell anything when I was down there with the engine off and with it on with the AC on. I didn't see any fluids or anything.

Now, when I was in Vegas I dont know if it was the heat or what, but the AC would be cold, but not THAT cold. Say it was 110 outside, the inside of the cab would be 85. Maybe 80. Could I just need a recharge? I was under the impression the AC system was sealed and the only time a recharge is necessary is when there's a leak.