I don't think the temperature there is about -16c. They wouldn't even be able to handle it bundled up, much less in short-sleeved shirts. 16c, maybe, but not -16c.
((For reference, 16c is about 60f, -16c is about 3f.))
I think she means that them ascending to 2600m caused the temperature to drop by 16c relative to the sea level. So if it's a sweltering 35c in Tokyo, it's a nice 19c in the mountains.
@Nine_Gates@JumboWheat01
Yeah, that's right.
The original text reads "バスとロープウェイで…一気に2600m上がったからね…(大体 ‐16C分)" which I translated literally to it "(being around -16C)". That phrase on its own probably wouldn't mean a drop in temperature, but in this context it does.
Obviously wasn't thinking seeing all of them dressed so lightly in -16C lmao