The Marietas Islands lie in Banderas Bay off the Nayarit coast, accessible by boat from Puerto Vallarta, Punta Mita, or Sayulita. Designated a Marine National Park and a UNESCO Biosphere Reserve, the islands present a volcanic underwater landscape of pinnacles, walls, caves, drop-offs, and reef. Sites range from shallow beginner dives to deep, current-swept passages for advanced divers. Green, hawksbill, and Ridley turtles are recorded here alongside whale sharks, nurse sharks, panamic green morays, and a variety of nudibranchs. Water temperature varies noticeably across the year, cooling in spring and warming through summer into autumn.
Monthly water temperature across Marietas Islands's sites, from satellite sea-surface data corrected for depth. The band shows the site-to-site spread.
Water temperatures follow a clear seasonal pattern: coolest in the spring months and warmest through late summer and autumn. The November-to-April window is generally considered best for larger wildlife encounters, and currents at some sites can be strong enough to restrict access to experienced divers.
Water temperature around Marietas Islands ranges from about 21°C in March to 30°C in September, based on satellite sea-temperature data for its dive sites.
In the warm season (about 30°C) a rash guard or 3mm shorty is comfortable in Marietas Islands; in the coldest months (about 21°C) step up to a 5mm suit.
Fin maps 6 sites in Marietas Islands (6 scuba diving sites).
Across Marietas Islands's dive sites, May, June, July, August, September and October are most often reported as the best months to visit.
2 more sites to explore
