Here's the sentence.
The fact that Ella’s moods were as mercurial as the weather was problematic for her relationships—it didn’t help that she lived in Chicago.
I would like to ask what's the relationship between Ella's unstable moods and Chicago? My hunch was that the weather there was always clear and sunny, making people tend to be in good mood but google showed it wasn't really the case. It is cold and windy in winter.