Going to disagree slightly with the find-a-stable-spot advice, or at least add to it. I did exactly that, moved everything to the cellar, and my ferments got stable and boring.
The cellar sits at about 11 all year. Kraut takes two months and nothing else really goes at all. Stable is not automatically better, it needs to be stable at a useful temperature, and a lot of the "boring" places people recommend are boring because they are cold.