Month-specific sea-surface temperature · Mexico

Isla Mujeres Sea Temperature in December

27.5°C

81.5°F

In December, sea-surface temperature near Isla Mujeres has a historical monthly average of 27.5°C. This is not the reading for any particular holiday date.

Across 2022–2025, the lowest and highest yearly December monthly means were 27.1–28.0°C. These are not daily extremes.

Previous month

November · 28.5°C

Change into December: -1.0°C

Next month

January · 26.7°C

Change into next month: -0.8°C

Can you swim or snorkel in Isla Mujeres in December?

At 27.5°C our temperature-only guide describes the water as warm water. Comfort depends on your cold tolerance, immersion time and wind. A historical average cannot determine whether conditions are safe on any given day.

Do you need a wetsuit?

Most people are comfortable in swimwear or a light rash guard.

Which beach should you choose?

Look for a beach sheltered from the actual forecast waves and wind on your visit. Exposure, currents and entry conditions vary even where water temperatures are similar. Follow local warnings.

Check the current waves, wind and snorkeling forecast →

A live forecast does not predict a future December. Check again close to your trip.

Isla Mujeres Sea Temperature: All 12 Months

Choose a month for available historical evidence, month comparisons and swim guidance. Missing history is clearly marked and never presented as a long-term normal.

January 26.7°C February 26.6°C March 26.9°C April 27.2°C May 27.7°C June 28.6°C July 29.0°C August 29.2°C September 29.6°C October 29.4°C November 28.5°C December 27.5°C

Data source and limitations

Source: Open-Meteo Marine API, MeteoFrance sea-surface temperature; 2022–2025. Marine model grid near 21.23, -86.73. Based on 4 yearly monthly means and 2976 recorded samples. Source methodology.

Modelled sea-surface temperatures do not establish underwater visibility, wildlife, calm currents or safe entry.