Skies are sometimes just like that....we have the same issue here in Maine...sometimes they are so light grey they are colorless. In this case, I really like how the steel grey sky echos the grey street. Nicely done! The bracketting suggestion is a good one, I often take one under exposed and one over exposed by just a stop to see which looks best. Replacing skies is never a good idea in my opinion, the light in the photograph will look unnatural when that is done, and it's almost always quite obvious.
Nice shot, and much less noise in this one. 4 stars!