You have to have internet connection, which is why I believe he said yes. If you don't have service of any sort, net or phone, will not be able to get any information loaded from any source.
I don't use the feature personally. To many things change in my area. I use absolute barometric pressure from my kestrel or Leica, temp from either source or even from my truck if I am not hiking. I don't worry about temp changes unless the swing is beyond 20 degrees. It might be 25 when I leave the truck and 55 in the afternoon. I will input 35 and be dang close 80% of the day. If I have time when a shot op shows up I will input exact numbers, find the solution, shoot.
Good luck