Around what wind speed does the kilt tend to move around enough that bystanders can tell whether or not the kilt-wearer is/isn't regimental? And if it varies with the kilt (5 yard, 8 yard, 16 weight wool, 13 weight wool, PV), what should I expect within those variations?

Obviously the wind speed can change temporarily (i.e. wind gusts) or in certain locations (i.e. in downtown locations where the wind gets funneled down certain streets). But I'd like a general idea of what to expect.