Where is the latitude of marriage in the United States?

Is there a relationship between latitude in the northern hemisphere to abundance of marriages? I'm starting to think so, 'cuz I'm finding out that more and more of my friends back down in Los Angeles, Orange County, and San Diego are all getting engaged like it's the final rites of spring.

Of course, I'm very happy for them, as I am very happy for my married and/or engaged friends here in Seattle -- and I wish them the very best. But I have to reiterate that I'm glad I live in a town where marriage is not something that's, well, as expected in one's life path.

But seriously, this South U.S./marriage thing... what's up? Where's that magic line of latitude which dictates that all peoples south of it have to get married?

This is why we have scientists, dammit! Someone's seriously asleep at the whip here.