For me, it's not about the length or the scale of the temperature, it's having grown up with the "feel" or the "time" of a measurement. If I see a road sign th

For me, it's not about the length or the scale of the temperature, it's having grown up with the "feel" or the "time" of a measurement. If I see a road sign that says it's 130 miles to Chicago, then I know how much time it's going to take me to get there. I don't have that "feel" for seeing 209km. If I see it's 60° (F) out, I know how that feels, I know how to dress for it. I have a very different expectation if I see it's 15° (C). I personally think that's the biggest barrier to conversion, the learned, in-grained expectation of time or sensation when seeing a measurement expressed.