Coastal Southern California is one of the gentlest wood environments in the United States, and the number that proves it is published by the USDA Forest Products Laboratory. The Wood Handbook prints month-by-month equilibrium moisture content for US locations, and the nearest listed station to Huntington Beach, Los Angeles, reads 9.4, 10.2, 10.5, 10.4, 11.0, 11.7, 11.6, 11.2, 10.8, 10.6, 9.8 and 9.9 percent across the twelve months. The whole year fits inside a 2.3 point band.
Compare that with the same table's other entries. Fresno runs from 15.8 percent in January to 7.4 in July, a band of 8.4 points. Chicago spans 12.3 to 15.1. Las Vegas drops to 3.7. Wood moves when the moisture around it changes, so the size of the annual swing is the thing that opens panel gaps, cracks mitres and sticks doors. On that measure the Orange County coast is close to the easiest address in the country.
Salt air is still a real material problem here. It attacks unprotected steel, so hinge and runner plating, screw choice and any exterior joinery genuinely do matter within a few blocks of the water in Sunset Beach and Huntington Harbour. What it does not do is wreck interior cabinet carcasses, and any quote that leans on that claim is selling worry rather than cabinetry.