I live near Wildcard and I have to agree with him... you won't find a house here without warm clothing and basic supplies like flashlights, etc. And I'm talking about in-town - the country dwellers are self sufficient and could be for months most likely. If you mean major urban areas like Chicago, St. Louis or more minor ones like Peoria, Quad Cities, Bloomington Normal, I have no idea which is more "prepared" and I doubt anyone could effectively answer that. Your bet is likely a safe one to make since nobody could tell you who won. <img src="/images/graemlins/smile.gif" alt="" />
SF and other CA residents are reminded to maintain emergency supplies more often than their urban compadres in Chicago. I've been in both cities for quite a long time each, and I can confirm that fact at least. We've got floods and tornados (or tornadoes if you like) which both tend to be fairly localized and we get some warning most of the time. Plus they don't generally wipe out infrastructure, especially larger bridges and such.
I would be much more worried about living in the bay area. I've spent over a year living there in the last 10, thankfully uneventful. We do get the occasional quake (
New Madrid fault) though.