I would rule no. Terrain is more than the ground you're standing on.
I use a Decanter of Endless Water to fill a dungeon pit with 3' of water, am I in Aquatic Terrain?
I dump 80 lbs of sand out of a Bag of Holding in the middle of the jungle, am I in Desert Terrain?
I use my Apocalypse Oracle revelation to create lava on the ground, am I in Volcanic or Mountain Terrain?
My opinion is that all of those answers are no. I'm not sure the rules define what constitutes a terrain, but I would base it on the predominant terrain of a certain area or, for certain domains like Cave, Aquatic, and Urban, if you are inside a location that qualifies.
While I might agree on the others, I'd say that flooding an entire dungeon might count for acquatic terrain
Doesn't any underground manufactured space count as 'urban' or 'dungeon'? (RAW question)
Shouldn't even an urban Druidic Grove count as 'forest'? (RAI question)
(And both rhetorical)
The rules do not define what constitutes a terrain.
Filling a dungeon with water could actually be aquatic terrain, as no weather effects define it (as in desert). Sleet Storm is not the ice on the ground. It is the result of the 20-ft high sleet, making a 40ft raduis x 20ft high area a snowstorm above frozen ground.
If you already "know the answer" why are you here asking the question instead of asking your GM to allow it?
For the record I'm of the "it isn't" terrain for the purpose of ranger abilities or the like, but difficult terrain as detailed mechanically and that is flavor text for the effect. The same way ruins in a forest would provide mechanical cover and difficult terrain, but you would be in a forest, not urban area. Terrain has multiple meanings in the game. The entire "picture" needs to be considered, forest for the trees and all that.
Sleet Storm spell description: "causes the ground in the area to be icy"
Ranger Favored Terrains entry: "Cold (ice, glaciers, snow, and tundra)"
Is it possible for a Winter Witch to cast Sleet Storm on her area, effectively being in icy terrain, gaining the Druid Spell SLAs?
Just capture the following monster under your control:
http://www.d20pfsrd.com/bestiary/monster-listings/undead/yuki-onna
Then youll have a portable blizzard all day everyday!
Though, I mean, I suppose talk to your gm about ruling it in your favor though.
The way I look at it:
Sleet storm is a lv3 spell
Fey magic gives you access to 1/day lv 1 and 0 spells.
its hardly in any way "broken"
If a specific terrain falls into more than one category of favored terrain, the ranger's bonuses do not stack; he simply uses whichever bonus is higher.
A terrain being one type doesn't keep it from being additional types. Ruins in a forest could be forest, mountain and urban all at the same time.
My GM allows it, I was more fishing for an answer like "X spell does it better" (until she gets Control Weather) and I was hoping for a definitive answer and RAW definition of "terrain" :P
A 40-ft garden of exotic plants would definitely count as jungle terrain in my opinion, by the way.
@Fernn, the reason I came up with all this is that our Winter Witch could flavorfully cast a Sleet Storm around her and feel "stronger" while in a non-wintry environment, her player is all about flavor and I found it to be a cool idea.
Yeah my exact inclination, as long as its favorable, and ok with your GM(which I doubt he would have any objection) then sky is the limit.
If a specific terrain falls into more than one category of favored terrain, the ranger's bonuses do not stack; he simply uses whichever bonus is higher.A terrain being one type doesn't keep it from being additional types. Ruins in a forest could be forest, mountain and urban all at the same time.
It could be anything and everything your GM wants it to be, but the reality is most adventures will say "forest" and have difficult terrain in the aspect of ruins or various other non forest details. You are still in a forest, not an urban city area.
What it is, is much more important and pertinent, than what it could be if you reason it out to the Nth degree.