No you can't, it just turns the background yellow.
EDIT: the snow stops _but after a few seconds_. I toggled it to find out if it would turn off the snow, and the immediate feedback was that it doesn't. That's really _really_ bad UX.
I get the site has a frivolous feel, which I do like. And there's no problem with snow if you can turn it off. But it _seems_ like you can't turn the snow off, at which point it does become annoying.
And it's actually making a serious point about something I care about, so I actually wanted to read the article (which I did through the snow).