I was born and raised in California, and I’ve never heard a native call it ‘Cali’. (Except for one guy in WA, who was a native but spent a lot of time in WA.) I call Southern California ‘Southern California’ or ‘SoCal’, Northern California ‘Northern California’, and California ‘California’.
You?
I had one irratating co-worker in Atlanta call that state “Cali”. She also referred ti Cincinnati as “Cincie” and San Fransisco as “Frisco”.
Maybe she just didn’t like saying entire nouns.
Ugh.
The Beastie Boys.
That’s the only time I’ve ever heard California called “Cali.” I’m in New York, if we’re looking for regional patterns.
I hate when people refer to Chicago as Chi Town. It’s just stupid.
I’ve only heard it abbreviated like that when used as an adjective, usually for food – “Cali Burger”, “Cali Roll”. Never actually used the state.
To be fair, it’s about as stupid as “Chicagoland” (as if it is its own country).
I grew up in LA, lived there for almost thirty years, and never heard anyone refer to California as “Cali” until a few years after I moved away, by someone who claimed to be native.
You know they’re not, if they call it Cali. (The other dividing line is how they refer to the freeways.)
I have never heard it called Cali, except once, by my college roommate. It never happened again. 
It’s always reminded me of an amusement park (which it can be, at times). Do other cities incorporate their surrounding towns into a “Land”?
We need a king.
Call it “Cali”?
I don’t think so.
I hear it quite a bit in Vegas .
NoCal native here - Johnny L.A. has it right in the OP - no self-respecting native refers to it as “Cali”
I first heard it in the song “Going back to Cali” off the, what, Less than Zero soundtrack? I think it was LL Cool J.
**sciurophobic ** - what your post a reference to that? That line is used in the song…
Yep here it is (Amazon link).
So one James Todd Smith from Queens appears to have come up with this nickname - and no locals picked it up…
I do (especially because it annoys my roommate who grew up in Cali), but it feels like something I specifically picked up somewhere- though I can’t remember from what.
I’m from Philadelphia.
I’ve never heard California called “Cali”, but I’m not a native.
I am native to Ohio, and “Cinci” is a not uncommon nickname for Cincinnati.
I once heard someone say he had recently visited Cali. I thought he was referring to the city in Columbia and asked him all about it, and was confused by the subsequent conversation.
My mom’s from LA. She has never called California anything but California.
No one here abbreviates it, it’s california burger or california roll.
I say let all the non-californians say it, that way we weed out the ones that have actually been here or lived here from the rest. 
I’ve never heard someone from Southern CA say it, but I have heard a few Northern CA people say it. That said, I mostly hear it from non natives who think they are being cool.
I will occasionally shorten it that way when I write in my blog about how much I like living in this state.
But as Campion said, my most distinguishable non-native characteristic is referring to highways as “Route [insert]”-Route 110 or Route 405 or whatever. As soon as I say something like “well I take the metro from Fillmore but sometimes I drive down Route 110 to park at Avenue 26” I usually get the “YOU’RE NOT FROM AROUND HERE ARE YOU???”
I fully intend to continue misidentifying highways in this manner, refusing to wear a parka and mittens when the temperature dips below 68, wearing black/grey/plum and other severe colours, layering with sweaters in the middle of summer, talking ecstactically to people about their fruit trees, saying “wicked [insert]” instead of “hella” and otherwise bumbling about as an East Coaster. I’m never going to be a Native so I have no intention of attempting it.
Southern California != California. They can keep their "the"s.
Aside from Biggie, I don’t think I’ve heard anyone refer to “Cali.” It just screams “trying too hard.” Unless you’re Biggie.