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

The temperature in Cozumel hits its lowest levels in January and December, recording an average high-temperature of 28.6°C (83.5°F).

Heat index

The heat index for December is calculated to be a tropical 34°C (93.2°F). Take more preventive steps, risk of heat exhaustion and heat cramps is elevated. Long activity may culminate in heatstroke.
Remember that heat index calculations are made for conditions in the shade with light wind. Exposure to direct sunlight may make the heat index values climb by 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'real feel' or 'apparent temperature', is an amalgamation of air temperature and humidity to express the equivalent perceived temperature. The influence of weather is personal, with a diverse population experiencing it differently due to differences in body mass, stature, and degree of activity. It is noteworthy to mention that direct sunlight exposure can augment the felt temperature, leading to an increase in the heat index by 15 Fahrenheit (8 Celsius) degrees. Heat index values are extremely significant for children. Children commonly overlook the importance of rest and fluid replenishment. Thirst, being a delayed sign of dehydration, emphasizes the need to keep hydration up, especially during lengthy physical activities.

Humidity

The average relative humidity in December is 83%.

Rainfall

In Cozumel, in December, it is raining for 9.8 days, with typically 107mm (4.21") of accumulated precipitation. Throughout the year, in Cozumel, Mexico, there are 119.9 rainfall days, and 1490mm (58.66") of precipitation is accumulated.

Sea temperature

In December, the average sea temperature in Cozumel, Mexico, is 27°C (80.6°F).
Note: Between the temperatures of 25°C (77°F) and 29°C (84.2°F), water is considered very warm, providing pleasure in water activities without discomfort over lengthy periods.

Daylight

With an average of 10h and 54min of daylight, December has the shortest days of the year in Cozumel.
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 December, the average sunshine is 6.2h.

UV index

January and December, with an average maximum UV index of 7, are months with the lowest UV index. A UV Index reading of 6 to 7 represents a high health vulnerability from unsafe exposure to UV radiation for the ordinary person.
Note: A maximum high UV index of 7 in December translates into the following recommendations:
Eschew overexposure. Those with light skin may suffer burns in fewer than 20 minutes. Limit direct sun exposure and seek shade between 10 a.m. and 4 p.m., the time of the most intense UV radiation, noting that shade structures may not provide total sun protection. Outfit yourself in sun-safe attire, like long sleeves, pants, a hat, and UV-blocking sunglasses. Caution! Sand and water surfaces escalate the UV intensity from the Sun.