Have a stout fermenting in my closet at the moment, just a tad concerned about the temp, its a little nippy, not too cold though, id expect the temp in the closet to be around 15 degrees celcius or 59F. Is this a little low?
Well, remember that fermentation itself will add a few degrees to the beer's temp above ambient. You might be better off with ambient around 62°-64°, but you may well be fine now. Are you seeing signs of an active fermentation? I'd rather be too cool than too hot any day of the week.