Vandenberg has warned people in Santa Barbara, San Luis Obispo and Ventura counties that they might hear multiple sonic booms as the Falcon 9's first stage touches down at the base's Landing Zone 4.
SpaceX has flown boosters back to land after launches from Florida but has yet to do so in California.
A graphic explaining sonic booms, provided by Vandenberg Air Force Base ahead of a planned SpaceX launch on October 7, 2018.
SpaceX's Falcon 9 rocket as seen from the North Coast. "A sonic boom is the sound associated with the shock waves from an aircraft or vehicle traveling faster than the speed of sound".
The fact that the launch and landing took place near Los Angeles meant there were ample opportunities for Southern Californians to catch the show (and for unwitting observers to register UFO reports).
Such landings are part of SpaceX's push to develop fully and rapidly reusable rockets and spacecraft, a breakthrough that company founder and CEO Elon Musk has stressed could cut the cost of spaceflight enough to make grand exploration feats such as the settlement of Mars economically feasible.
The loudness of the boom will depend on the weather and other conditions, officials added.
The rocket will be carrying an Argentinian Earth-observing satellite, known as SAOCOM-1A, into orbit.
Later, SpaceX reported that the SAOCOM 1A radar satellite was placed in its proper pole-to-pole orbit.