FWIW, I’ve heard that if you let vines grow directly on the exterior (or if you run cables and plant the kind of vines that need to climb cable), the vegetation will insulate/shade the house from the extreme sun.

I can’t say it’s 1st-hand knowledge but perhaps worth looking into. Evaporatie cooling might have a small role in that too. Of course the caveat is if you let vines grow directly on the stucco, they will destroy the stucco which many folks consider a bad trade-off. The other caveat is plantlife brings insects so you might not want to bring insects right up to your walls.