Del Mar weddings are usually mid sized and coastal, and they lean more polished than the beach towns further north. Powerhouse Park and Seagrove sit right on the sand with the village behind them. Above the town, bluff top venues look down the coast toward Torrey Pines. Guests tend to stay in the village and walk, which makes the day feel contained in a way most San Diego weddings are not.
Race season is the thing that reorders everything. The Del Mar Fairgrounds runs the county fair from June into early July and the racing meet from mid July through Labor Day, with a shorter meet in the autumn. On those days traffic on Via de la Valle and the coast road slows to a crawl from late morning, parking in the village disappears, and hotel rates climb. It does not make a wedding impossible. It does mean telling guests to arrive an hour earlier than they think they need to.
The light on the bluffs is the reason people book here. Late afternoon in September and October gives an hour of soft coastal light with the marine layer usually burned off by then. Down at Powerhouse Park the tide matters, because a high tide at the wrong hour takes most of the usable sand. Check the tide chart for your date before you commit to a beach ceremony time. Park ceremonies need a permit from the City of Del Mar and the rules on chairs and sound are specific, so confirm them directly.
Then there are the trains. The coastal rail line runs along the bluff and a train passes every hour or so. It is loud for about forty seconds. Plan the vows away from the timetable if you can, and if a train comes anyway we stop, wait, and pick the sentence back up. Guests remember it fondly.