I've been struggling with this for a while, used/"hacked" vanilla scripts but, well with success, but not what I want.

Player climbs mountain (imagine Throat of the World) weather changes as player ascends from nice and sunny down below to snowy, whatever as player ascends. So far I have used a trigger box with simple OnTriggerEnter SetWeather script. This works fine as expected, it snows as player approaches summit. Changing the weather back to what it was when the player descends is an issue. I know the GetCurrentWeather can use this somehow but I'm unsure how. If I stick with the trigger box approach, which I prefer, I need that when the player enters the trigger the weather is changed to snowy (ascending) and when again the player enters the trigger box (descending) the weather is restored to its previous, Enter/leave triggerbox is all in my mind but can't get my head around it. Help appreciated as always guys. Thank you.