I do apologise if it bothers you. [He says just as calmly, without making any promises to stop.] Yet for a butler to lose his head in the face of a calamity... [well. It just wouldn't do.]
[He turns smoothly on his heel so that they're facing the window together. Although he has the same visible breath going on as Sherlock he's not shivering, and simply clasps his hands behind his back.] At this precise moment? Nothing at all, no. [Possibly implying there have been intriguing things at other moments.]
Since it is so quiet, watching the flurry was simply the closest thing to stimulation, that is all. [Stagnancy makes him antsy, and although whirling snow is a poor excuse for visual stimuli it's better than nothing.] That is, of course, before you joined me.