This is 100% difficult terrain from here on out. Things you can not do in difficult terrain: You can not run, charge, 5 foot step or move at your full speed (unless you have said tool to do so). Your movement is reduced by half, unless you have snowshoes, then reduced by a quarter - " Snowshoes reduce the penalty for walking through heavy snow by 50%; for example, if moving through snow normally costs you 2 squares of movement per square traveled, snowshoes reduce this cost to 1.5 squares per square traveled."
Also, it is now snowing!!! That's right. You will forever now have a -4 to sight perception (while outside) and a -4 to all ranged attacks (including rays, while outside).
Lastly, the temperature here is cold; every hour spent in here requires a fort save to avoid taking 1d6 nonlethal. However, if you have cold resistance, and many do - you don't have to roll it