This has been an interesting fall for me, I had always associated the yellowing leaves of the hostas and probably all other plants with falling temps. This fall we have only had one near frost event, but it did not happen; overall the temps have been extremely moderate. I'm thinking the leaves turning has more to do with photoperiod vs falling temps. Probably the falling temps accelerate the process. Its been a very unusual fall for my part of Minnesota.
What does it mean in the big scheme of things, probably nothing, I was just surprised I had not known this, or I did know and have forgotten it. : ))))