Short answer? It's highly unlikely.
First of all, Russia has about 1,200 deliverable nuclear warheads. Probably less than one thousand sit on nuclear missiles. China has maybe 300-400. North Korea perhaps a dozen capable of making it to California. Not all the warheads can be fired off at once because some weapons have to be reserved for a second strike or attacking another nuclear power. So perhaps 500 or so Russian warheads would be targeted on the US.
In a Russian scenario, I'd say that major military bases will be targeted. China may only go for major West Coast military installations and population centers. When you can only shoot off say 200 warheads against an adversary who has that many to spend "freely" against an attacker like China, you want to do maximum psychological and political damage. That's done by killing civilians. This is known as countervalue targeting. "Will you trade Los Angeles for Taiwan?"
Russia operates on this strategy too, but has the extra warheads to blast military targets. Going strictly after nuclear targets is called counterforce targeting. This strategy risks wasting a warhead on nuking an empty silo as the other guy got his missile off in time. Russia has the numbers to do this. Until the end of the decade, Russia doesn't. So what that means is some military bases and major metropolitan areas.
Hey, it's an air base, right? A nice, long 11,000 foot runway would be perfect to park bombers on, right? Except the Air Force doesn't disperse bombers like it's 1952. Point Mugu has nothing strategic there. In a shooting war, several conventional cruise missiles with regular explosives could destroy the E-2 Hawkeye squadrons and any maritime patrol aircraft that might be parked there. Nothing you need a nuke for, although an airburst weapon would stop flat the sheet metal hangers and aircraft like crushing a beer can.
China might want to destroy West Coast ports to harm the Navy's operations. Destroying a port is more difficult than an airbase. A cruise missile can't put a hole in water, nor are they very good at blowing up the concrete quays. A nuke detonated at ground level will do that, creating a large crater and making the place too radioactive to use for a long time. An airburst will irradiate the ground and trash the cranes but leave the concrete intact.
Now no important ships are based at Port Hueneme. It's a home for Seabees and testing. Target ships show up to be shot at or obsolete ones are used as test beds. Mainly, it's a commercial port. The only deep water port between Long Beach and San Francisco. That is a worthy target in and of itself. However, I don't think it would be nuked.
In my book Late for Doomsday, I take some liberties with geography (like Oxnard has a hill) and I nuke Hueneme. In real life, the port is just too small. Major disruption could be done with cruise missiles and sabotage. Remember the ship that got stuck sideways in the Suez Canal? A ship could be sunk in the entrance to Port Hueneme. Cruise missiles could sink ships tied up along the quays or destroy important port facilities. Rendering the port unusable for several months would cause issues with American shipping and force Seabees and Marines to embark from LA or San Diego, creating a choke point.
Nuclear weapons are weapons of last resort. Nuking Port Hueneme at the end of a war in desperation doesn't help China win the war. What's more scary is the thought of a Pearl Harbor in California. Chinese Navy SEALs hijacking a cargo ship and sinking it in the harbor, followed by a cruise missile attack, is well within the realm of possibility for any war with China. I'd expect that.
Yes, it was a former Air Force base. No, it is not going to be nuked. Bombers won't be dispersed there and nuking the airport that all the celebrities park their jets at isn't going to win a war. This isn't the early Cold War anymore.
The Air Force Base about 85 miles northwest of Ventura is a prime target. It launches and controls satellites. Yes, it also launches Minuteman III ICBMs, except those are demonstration tests and they are unarmed. No nukes are kept there. One airburst over the main base cantonment area would destroy a major chunk Space Force's military capabilities in space by destroying buildings and killing people. Again, the same thing could be accomplished with cruise missiles, although I'd think that cruise missiles would target the launch facilities rather than people.
I’ll be the first to admit that I don’t know if Vandenberg has any secret underground bunkers. I also don’t know if Russia might take a chance and use ground bursts to take out the two Minuteman silos. Ground bursts may be called for at Vandenberg, but I don’t know. I have factored fallout coming from Vandenberg into my calculations as possibility.
Edwards AFB and the Palmdale/Lancaster area
Edwards? Not so much. Just a test facility. The outskirts of Palmdale where Boeing and Lockheed have their “Skunk Works” facilities? That’s a definite possibility. Although you could cruise missile attack those by flying a couple missiles over Malibu and up the 14.
March Air Reserve Base
Good chance that hitting March in San Bernardino County overlaps with anti-population countervalue attacks on the LA basin. I would not bet against Russia nuking March.
I figure anyone nuking LA would drop around half a dozen warheads all over the city in a pattern intended to maximize death and destruction. This pattern would be unknown to all but the Russian or Chinese planners. If you live in the urban sprawl known as the Los Angeles area, get to the outskirts. Maybe a million people killed in the first day—one megadeath. But Ventura County is full. Try Barstow, Bakersfield, or Las Vegas.
Note: this an adaptation from my non-fiction book Suburban Warfare: A cop's guide to surviving a civil war, SHTF, or modern urban combat, available on Amazon.