There is a lot of ice, cold, wind and darkness in both symbolism and motifs in this novel, so the most prominent season is winter. For example, at Lowood, it is always freezing cold and when Jane wakes up in the morning, the water in the pitchers is often frozen. Whenever something bad happens, winter and winter holidays that indicate it is winter are referred to, i.e. "Christmas cold". The fields are often frozen or covered with a hoar frost, there is a great deal of biting wind blowing all the time. When Jane is living with St. John and his sisters, she often uses cold, dark imagery to describe St. John himself.
Since the novel is set in northern England, we are always getting a sense of a cold, forbidding landscape that is a harsh place to live in. Bronte describes her setting with vivid details, so one can almost feel like one is actually there. Brrrr.