[...Arendelle? He was from Arendelle. What were the odds of that?]

I'm from the Southern Isles, [he remarks, still frowning slightly, before he continues talking,] but I was in Arendelle before I was brought here. Cold...snowy...eternal winter Arendelle.

[which, based on the fact that Kristoff had taken off winter clothes, he's assuming that Arendelle is still in eternal winter for him.]