December weather forecast
Cozumel, Mexico

December marks the end of the year with the onset of winter, characterized by shorter daylight hours and a further drop in sea temperature. The UV index decreases to 7, but sun protection remains advisable during peak sun hours. Albeit lower on the scale, a temperature range between 20.3°C (68.5°F) and 28.6°C (83.5°F) provides generally pleasant weather. Contrary to November, December experiences a lower amount of rainfall to the tune of 107mm (4.21").

Temperature

During January and December, Cozumel experiences its lowest temperatures, averaging a high-temperature of 28.6°C (83.5°F).

Heat index

The average heat index in December is computed to be a tropical 34°C (93.2°F). Ensure extra safety measures, heat exhaustion and heat cramps are likely. Continuous activity might result in heatstroke.
Observations indicate that the heat index values are for shady locations with light wind. Heat index values may be hiked up by 15 Fahrenheit (8 Celsius) degrees under direct sunshine.
Note: The heat index, also known as 'felt air temperature' or 'real feel', is a composite of temperature and humidity figures to convey how warm it feels. An individual's perception of weather can be influenced by a variety of factors including metabolic differences, being pregnant, and their degree of physical exertion. It is noteworthy that being in direct sunlight can enhance the weather's impact, raising the heat index by as much as 15 Fahrenheit (8 Celsius) degrees. Heat index values are essentially critical for children. Young children typically face greater hazards than adults because they do not sweat as much. Their larger skin surface in comparison to their little bodies and the high heat production from their active nature compounds their vulnerability.

Humidity

In Cozumel, the average relative humidity in December is 83%.

Rainfall

In Cozumel, during December, the rain falls for 9.8 days and regularly aggregates up to 107mm (4.21") of precipitation. In Cozumel, during the entire year, the rain falls for 119.9 days and collects up to 1490mm (58.66") of precipitation.

Sea temperature

In Cozumel, the average seawater temperature in December is 27°C (80.6°F).
Note: Surface water temperatures falling between 25°C (77°F) and 29°C (84.2°F) are regarded as prime and extremely agreeable for enduring periods during any water activity.

Daylight

December has the shortest days of the year, with an average of 10h and 54min of daylight.
On the first day of the month, sunrise is at 7:07 am and sunset at 6:06 pm. On the last day of December, sunrise is at 7:23 am and sunset at 6:18 pm EST.

Sunshine

In Cozumel, Mexico, the average sunshine in December is 6.2h.

UV index

The months with the lowest UV index are January and December, with an average maximum UV index of 7. A UV Index estimate of 6 to 7 represents a high health hazard from unprotected exposure to Sun's UV rays for average individuals.
Note: The UV index of 7 in December translates into these instructions:
Embrace precautions and observe sun safety norms. Evasion of sunburn is a necessity. Between 10 a.m. and 4 p.m., UV radiation is strongest. Make an effort to avoid direct sunlight during this time, remembering that shade structures may not provide full sun protection. A hat with a generous brim can prevent nearly 50% of UV rays from reaching your eyes. Caution! Sand and water reflections can notably increase the UV radiation intensity.