San Juan del Sur [1]’s mellow, year-round party scene picks up around Christmas, New Year’s Eve, and Semana Santa when the town is flooded with visitors. Managuan club owners set up beach discos during the high season.
The rest of the year, the town’s only disco, Crazy Crab (at the north end of the beach—take a taxi home at night), is open Thursday–Sunday (Saturday night is the best).
San Juan del Sur’s Bermuda triangle of bars, Iguana, Marie’s Bar, and Tsunami, cater to locals and foreigners alike. Iguana’s upper level heats up late night; Tsunami plays reggae.
A bit farther down the strip is another enjoyable waterfont bar, The Pier with a more chill vibe.
San Juan del Sur’s fiestas patronales are June 16–24, with bull riding, pole climbing, greased pig catching, and Coca-Cola chugging contests, followed by Procesión de la Virgen del Carmen on July 17. Locals parade the icon, the Patron Saint of Fishermen, through town and to the docks where waiting boats take her (and as many locals as possible) for a lap around the bay.
On September 2 the town commemorates of the tidal wave of 1992, a 62-foot monster that swept across main street, destroying many structures (and farther up the coast, entire villages, like El Tránsito).
Links:
[1] http://www.moon.com/destinations/nicaragua/southwest-coast