I see the the graphic option "weather effect", but i have never see rain or other effects. This feature will be introduce in future releases?
If so I think weather should be not only a graphic effect, but it should affect gameplay.
Storms (of snow or sand) and fog should shorten soldiers visual range.
Rain (as snow i think) should affect the movement speeds on earthy grounds.
Extreme temperature (very high and very low) should affect some weapon efficency (ex: lasers suffer high temperature cause low heat dissipation) and/or affect soldiers status (loss of action points and or loss of precision).
Strong wind (so the storm) affect bullets trajectory so weapon as sniper shotgun have a precision malus on long distance.
And so on.
PS:sorry for my english, i hope what i write is understable.