June - August
Hilton Head's year-round warm weather makes it a popular winter getaway. That said, summer's also high season here, as families come to enjoy their vacation homes during their children's summer vacations. Christmas on Hilton Head is a longstanding tradition with many homeowners, some of whom prepare elaborate feasts in their beachside villas. There are big spikes in prices around Christmas, New Year's, Labor Day and Memorial Day.
March - April
Early spring in Hilton Head can be a bit gray and dreary. It's not enough to deter many beach-goers, but golfers can get rather snitty when their tee times get called off due to thunder, so this is generally the quietest time on the island. If you're not interested in golfing, this is a good time to get in on major island bargains. Call ahead for package deals at the resorts, many of which slash prices during slow season.
Late spring is Hilton Head's shoulder season. The weather's idyllically pretty, all blue skies and fluffy white clouds and 72 degree days, but most island summer homeowners haven't descended yet. The beaches are blissfully empty, and you can snag reservations at even the best restaurants with total ease. Traffic begins to spike around Memorial Day and stays high all summer.