By vinyl, do you mean the PVC white rail fencing? If so, that's what we have since that's what our HOA approves. It's been good fencing as far as looks, but we have a strand of hot wire around the inside because it doesn't keep in my draft colt who tends to push on it. If you are just using it for a round pen and not leaving a horse in it long enough for them to test it, it would be fine. It doesn't get below 20 something here so we don't have issues with cold. We do have intense heat and that doesn't appear to have any effect on it yet.