Isla de Mona
Island Uninhabited Caribbean island and Puerto Rico natural reserve
An uninhabited island west of Puerto Rico’s main island, Isla de Mona is a government-protected nature reserve known for limestone caves, clear snorkeling waters, and endemic species. Access requires permits from Mayagüez; visitors are typically divers, researchers, and experienced campers.
Isla de Mona is an uninhabited island in the Mona Passage, administratively part of the municipality of Mayagüez, Puerto Rico. It is a protected natural reserve known for its karst limestone landscape, caves and endemic wildlife.
The island attracts visitors for snorkeling and diving on surrounding reefs, cave exploration onshore, and wildlife observation, notably the endemic Mona ground iguana. Archaeological remains and Taino sites are also present and of interest to researchers and visitors with permits.
Mona has a record of pre-Columbian habitation and later small-scale use for navigation and resource extraction, but it remains largely undeveloped and is managed for conservation. Modern use is limited to research, regulated tourism and occasional temporary camps.
The island lies in the Mona Passage between Puerto Rico and the Dominican Republic and is administered from Mayagüez, Puerto Rico.
- Access permits: Visits require prior permission from the Puerto Rican authorities; access is limited to protect wildlife and archaeological sites.
- Natural highlights: The island is noted for limestone cliffs, extensive cave systems and endemic species such as the Mona iguana, making it a conservation area and popular diving destination.
How to Get to Isla de Mona #
Boats depart from Mayagüez or Rincón; all trips require permits from the Puerto Rico Department of Natural and Environmental Resources (DNER) and coordination with licensed operators. The sea crossing can be rough; plan with an experienced operator and allow flexible timing for return due to weather.
Tips for Visiting Isla de Mona #
- Trips to Isla de Mona require an organized, licensed boat operator from Mayagüez or Rincón and a permit from Puerto Rico DNER - do not attempt the trip independently.
- Bring snorkeling/diving gear if possible: the underwater walls and coral formations are the island's real draw.
- Pack for a day on a remote, undeveloped island - shade is limited and there are no services except a small ranger station.
Best Time to Visit Isla de Mona #
Best visited in the winter dry season for calmer seas and clearer water. Access is controlled year-round.
Weather & Climate near Isla de Mona #
Isla de Mona's climate is classified as Tropical Savanna - Tropical Savanna climate with consistently warm temperatures year-round. Temperatures range from 20°C to 33°C. Abundant rainfall (1031 mm/year), wettest in October.
January
January is warm with highs of 29°C and lows of 20°C. Moderate rainfall (54 mm).
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February
February is warm with highs of 29°C and lows of 20°C. Moderate rainfall (36 mm).
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March
March is warm with highs of 30°C and lows of 20°C. Moderate rainfall (48 mm).
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April
April is warm with highs of 30°C and lows of 21°C. Moderate rainfall (76 mm).
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May
May is warm with highs of 31°C and lows of 22°C. Significant rainfall (121 mm).
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June
June is warm with highs of 32°C and lows of 23°C. Regular rainfall (91 mm).
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July
July is warm with highs of 32°C and lows of 23°C. Regular rainfall (86 mm).
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August
August is the warmest month with highs of 33°C and lows of 23°C. Regular rainfall (100 mm).
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September
September is warm with highs of 32°C and lows of 22°C. Significant rainfall (108 mm).
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October
October is warm with highs of 32°C and lows of 22°C. The wettest month with heavy rain (124 mm).
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November
November is warm with highs of 31°C and lows of 22°C. Regular rainfall (93 mm).
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December
December is warm with highs of 29°C and lows of 20°C. Regular rainfall (94 mm).
