Alright, so now I’m reading the old tale and I started to ask myself the same question. Thus, here and now, I’ve come upon your very same question thanks to Google. I think that the speculations above about the meaning behind Mr. Jarndyce’s words are more than correct – the reference to the East is simply a metaphoric device pointing to countless instances of the darkness rising up from Eastern winds. I believe, however, that the text has a simpler answer.
Ester and Ada’s own speculations in the book conclude the questionable nature of Mr. Jarndyce’s eccentric obsession with the winds when Ester explains that:
Ada and I agreed, as we talked together for a little while upstairs, that this caprice about the wind was a fiction; and that he [Mr. Jarndyce] used the pretense to account for any disappointment he could not conceal, rather than he would blame the real cause of it, or disparage or depreciate any one. We thought this very characteristic of his gentleness …" (end of Chapter VI).
Mr. Jardynce’s winds serve the purpose of developing Mr. Jardynce as a character in the novel and not so much to make discreet references to some meteorological anomaly.
Of recent, I can relate to the speculative advances from others about the meaning of “wind in the East” after living in the capital of the province of Cádiz in Spain for the last month. The infamous Levante, or “wind from where the sun rises” (levantar, in Spanish, means “to rise”), brings the heat of the Saharan Desert to Cádiz and suffocates everyone in the city, sending sand into my eyes on the beach and spilling it into the streets of the Maritime Walk. Coming from Africa, which here lies in the East, this wind is hot, not cold like the Eastern wind in the book which hits England from the chilly Balkan countries. Conversely, the Poniente, or “the wind from where the sun sets” (poner, in Spanish, means “to set”), enters from the West, across the Atlantic, pulling all the briskness from the surface of the ocean into the city to make the nights a little less sweaty and a little more sleepable.
Anyway, I guess I share all of that trivia with you in hopes of coming theologically closer to one of my dreams which is to eat in Apontiente, a contemporary, chic gastrobar here in the province of Cádiz before I have to leave the city and head back to native lands. If only I has the inheritance of Lady Dedlock!