How cold are you talking? IMO, cold temps are not going to speed flowering up, but possibly slow it down or cause problems if its too cold for prolonged periods. Try to keep your temps above 60-65F if you can. Preferably around 70-80, but do what you can do.It's cold here and I want to know if the cold when the lights are off. Can it make the flowering speed up? It looks like there a week or so ahead of what it took the last time. Same plants or type. I hope some one understands what I mean.