The distance from Ferndale to San Diego is over 2,300 miles. Flying from Detroit Metropolitan Airport (DTW) to San Diego International Airport (SAN) is the only practical method, taking about 5 hours in the air. Driving would take over 35 hours of active driving time.
Total Distance: 3,700 km driving, 3,200 km air distance.
Book flights with a layover in a hub like Denver or Phoenix to save money.
March to May or September to November for perfect weather.