as739x wrote:Great question, but this needed to be thought out a little more before asking. Your definition of an INTL airport is very loose. As the post above have picked apart. Try to narrow it down more. Because yes, the SF region is rare as it has 3 large international ops airports, with transoceanic flights, wide bodies by foreign carriers, etc.
But Joe Smith is going to reply here that ABC airport with on-call CBP is an Intl airport, and you can't argue they are wrong.
If you go by the busiest airports in the US by total pax for example, then yes SF would with the 7th, 36th and 41st busiest airports in the US (some would included SMF which is 42nd)
But long story short, if you can come up with some perimeters to this questions, its a good question.
Not only is the definition of international very loose an open to interpretation but how are we defining a region? I saw MDW-MKE-ORD mentioned above. From a geographic perspective MKE and CHI are certainly part of a region. But in that regard we could say that HNL, ITO and KOA are all "international" airports and HNL, KOA, LIH and OGG have commercial international services. That's 4 airports in the same region.
I think the question the OP is posing is, "is the Bay Area the only metro area with 3 large airports with commercial international/intercontinental operations in the US?"
77H