Marquesas Keys Island

Uninhabited coral islands west of the Florida Keys

A mangrove‑ringed atoll west of Key West, the Marquesas Keys attract charter boats, anglers and snorkelers for sandbars, shallow reefs and protected lagoons inside the National Wildlife Refuge.

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Marquesas Keys at a Glance#

About Marquesas Keys#

The Marquesas Keys are a small, uninhabited cluster of islands and sandbars off the coast of southern Florida, lying roughly 20 miles (about 32 km) west of Key West. They form an atoll-like group notable for shallow lagoons, sand flats, and marine habitat.

The area is valued for fishing, snorkeling, and wildlife viewing within a largely undeveloped setting; there are no built visitor facilities and day trips are by private boat or charter. The islands are managed as part of the Key West National Wildlife Refuge and are important for seabirds, juvenile fish, and seagrass ecosystems.

Historically the keys have been used by fishermen and visited for recreation; contemporary management emphasizes habitat protection within the refuge framework. Recreational use is seasonal and subject to federal wildlife regulations.

The Marquesas Keys sit in the Gulf of Mexico west of Key West, forming a remote reef and sandbar complex separated from the inhabited Florida Keys by open water.

  • Protection: Located within the Key West National Wildlife Refuge and subject to refuge regulations protecting wildlife and habitats.
  • Access: Reachable only by private boat or charter; there are no visitor facilities on the islands.

What to See#

  • Central lagoon: A shallow, atoll-like central lagoon accessed through narrow channels; supports seagrass beds and mangrove fringe and is the primary habitat for fish and juvenile marine species.
  • Sand and mudflats: Extensive sand and mudflats that are exposed at low tide and used by shorebirds and foraging fish, with low-lying keys and sandbars surrounding the lagoon.

How to Get to Marquesas Keys#

Charter a boat or join a day trip from Key West. There are no roads or scheduled ferries; access is by private vessel only. Visitors should follow U.S. Fish & Wildlife Service regulations and be prepared to pack out all waste.

Tips for Visiting Marquesas Keys#

  • Charter a small boat from Key West; many operators offer half- or full-day trips to the Keys and reefs around the Marquesas.
  • Bring cash and a cooler: there are no services on the islands and you must carry out all trash.
  • Respect restricted areas - parts of the Marquesas Keys are closed to protect nesting birds and fragile habitats; check the U.S. Fish & Wildlife Service regulations before visiting.

Best Time to Visit Marquesas Keys#

Best in the dry winter months for calm seas and visibility; always check refuge notices for closures.

Dry season
December-April · 22-28°C
Calmer seas and clearer water, best for snorkeling and boating.
Wet season
May-November · 24-31°C
Warmer water and higher humidity; afternoon storms more likely, which can complicate boat trips.

Weather & Climate near Marquesas Keys#

Climate

Subtropical climate with hot summers (peaking in August) and warm winters (coldest in January). Temperatures range from 18°C to 32°C. Abundant rainfall (1074 mm/year), wettest in September.

Air Quality: AQI 25 Good
Temperature & Rainfall
Temperature Range
32°
Warmest Month
18°
Coldest Month
Monthly Conditions
Month Comfort Temp Feels Rain Sky Humidity Wind UV Daylight
January - 18° - 24° 21° 61 mm - - 4.4 m/s - -
February - 18° - 24° 21° 46 mm - - 4.5 m/s - -
March - 19° - 25° 22° 51 mm - - 4.8 m/s - -
April - 21° - 27° 24° 51 mm - - 4.5 m/s - -
May - 23° - 29° 26° 89 mm - - 4.0 m/s - -
June - 25° - 31° 28° 145 mm - - 3.3 m/s - -
July - 25° - 32° 29° 108 mm - - 3.2 m/s - -
August - 25° - 32° 29° 146 mm - - 2.9 m/s - -
September - 25° - 31° 28° 150 mm - - 3.4 m/s - -
October - 24° - 29° 26° 116 mm - - 4.0 m/s - -
November - 21° - 27° 24° 56 mm - - 4.4 m/s - -
December - 19° - 25° 22° 55 mm - - 4.3 m/s - -