Salzburg's compact Alpine airport handles little beyond puddle-jumpers from Vienna or Frankfurt, which means every serious itinerary from Southern California funnels through a major European hub first. There is no nonstop option for business class from San Diego to Salzburg, so the real decision is which one-stop routing delivers the best long-haul product: Delta via JFK or Amsterdam using Delta One suites with sliding doors, United via Newark or Munich in Polaris business, or Austrian Airlines' own metal once you reach Frankfurt or Vienna. In practice, I've found the United routing through Munich particularly elegant for this city pair, since Lufthansa Group's Munich hub sits close enough to Salzburg that a well-timed connection can have you at the Hotel Sacher for a late dinner. Austrian's regional jets into Salzburg are modest, so treat that last leg as a formality rather than a splurge.
The long transatlantic segment is where you want to spend your upgrade instruments or miles. Delta One's suite, with its privacy door and Casper-designed bedding, remains the standout for red-eyes out of JFK, while United's Polaris seats on the 767 and 777 fleets offer solid direct-aisle access, particularly valuable on the 10-plus-hour crossing before you even reach the connection. My insider tip: build in a minimum three-hour connection at Munich or Frankfurt during winter months, since de-icing delays on the short Austrian Airlines hop to Salzburg are common between December and February and can strand travelers overnight in the terminal rather than at their alpine hotel.
Seasonality matters enormously here — January, February, March, October, and November consistently produce the softest business class fares on this corridor, largely because Salzburg's peak tourist crush (Christmas markets, summer festival season) pushes demand and pricing elsewhere in the calendar. Given how erratic award space and fare sales can be on these Delta, United, and Austrian routings, I'd strongly recommend setting up automated fare alerts for San Diego to Salzburg business class rather than checking manually — this route rewards patience and quick action in equal measure.
