Moderate sargassum is present today. Resort frontages may be cleaned, but independent beaches can have visible wrack. Ask locally which areas are clearest.
Key Biscayne sits at the northern entrance to Biscayne Bay, separated from the Miami mainland by the bay and connected by the Rickenbacker Causeway. The island faces east into the Atlantic, giving it direct ocean exposure and a cooling ocean breeze that makes it noticeably more pleasant than downtown Miami in summer. Biscayne National Park begins just south of the island, protecting 172,000 acres of turquoise water, coral reefs, and mangrove habitat: some of the most biodiverse marine environment in the continental US.
Key Biscayne's South Florida Atlantic location means moderate sargassum risk from June through September: similar to Miami Beach but the protected state park beaches are actively cleared and tend to have better conditions. Water quality here is consistently high; Crandon Park and Bill Baggs regularly appear on America's best beach lists. The proximity to Biscayne Bay's clear turquoise waters (best seen by kayak from Bill Baggs) makes this one of Florida's most visually stunning beach destinations.
The Cape Florida Lighthouse at Bill Baggs is the oldest standing structure in Miami-Dade County, built in 1825. It survived one of the most dramatic events in Florida frontier history: the Seminole Attack of 1836, during which Seminole warriors set fire to the lighthouse with the keeper and his assistant trapped inside. The keeper survived: barely: and the lighthouse was rebuilt and remained in service until 1878. Key Biscayne achieved brief global fame as President Richard Nixon's "Florida White House" in the early 1970s. Nixon's estate, "La Casa Pacifica" at the island's southern end, was where Watergate-era decisions were made during his winter retreats. The property was later demolished; the site is now part of Bill Baggs State Park.
"Your righteousness is like the highest mountains, your justice like the great deep. You, Lord, preserve both people and animals.": Psalm 36:6Live seaweed levels, surf, water quality and hotel deals — updated daily. Free.
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