Somehow I don't think Megakat City has a specific counterpart in the U.S.,
although we *have* seen the following:

Alkatraz Island ("The Metallikats") -- where Mac and Molly were imprisoned.
Analogous to Alcatraz Island, the famous prison up in San Francisco,
visible from the Golden Gate Bridge.  Alcatraz is no longer a prison but
now a tourist attraction, part of the National Park Service, if I remember
correctly.

Anakata Island ("Volcanus Erupts!") -- supposedly analogous to Hawaii, a
tropical resort paradise, complete with active volcano.

Megakat State Beach ("When Strikes Mutilor") -- This one I think looks very
similar to the Malibu/Santa Barbara coastline (anyone who's been in L.A.
and driven down the Pacific Coast Highway there would know what I'm talking
about).  Maybe I'm just biased because I live in L.A.  <grin>

Megakat Springs -- noted resort area, perhaps analogous to Palm Springs?

Gemkat Labs and the rest of the desert area where "Chaos In Crystal" takes
place   would be akin to either southeastern California, Nevada or Arizona
(tho I'm not sure about Arizona, never having been there).

Question -- have we actually seen snow in the series?  I haven't gone
through some of the episodes for a while, but I don't recall seeing any
snow in Megakat City.