, the first month of the winter, in Cozumel
, is still a warm month, with temperature in the range of an average high of 28.6°C (83.5°F) and an average low of 20.3°C (68.5°F).
The coldest months are January
and December, with an average high-temperature of 28.6°C (83.5°F).
In December, the average heat index is calculated to a tropical 34.2°C (93.6°F). Take extra precautions, as heat cramps and heat exhaustion are possible. Sustained activity may result in heatstroke.
Note that heat index values are valued for light wind and location in the shade. Exposure to direct sunshine can increase heat index values by up to 15 Fahrenheit (8 Celsius) degrees.Note
: The heat index, also known as 'feels like', 'real feel', 'apparent temperature', or 'felt air temperature', is calculated by taking the relative humidity value for a specific location and factoring it into the air temperature reading. Additional factors like differences in body mass, height, and shape, clothing, metabolic differences, and activity influence one's weather impression. Bear in mind that direct sunshine exposure increases weather impact, and may raise heat index by up to 15 Fahrenheit (8 Celsius) degrees. Heat index values are especially crucial for babies and toddlers. Young children are generally more endangered than adults, as they usually less sweat. And also, due to larger skin surface relative to their small bodies and higher heat production as a result of their activity.
In Cozumel, the average relative humidity in December is 83%.
In December, in Cozumel, the rain falls for 9.8 days. Throughout December, 106.8mm (4.2") of precipitation is accumulated. In Cozumel, during the entire year, the rain falls for 119.9 days and collects up to 1489.9mm (58.66") of precipitation.
In December, the average sea temperature is 27°C (80.6°F).Note
: For swimming, diving, and other water activities, temperatures between 25°C (77°F) and 29°C (84.2°F) are perceived as very enjoyable and pleasurable for prolonged periods without feeling uncomfortable.
The month with the shortest days in Cozumel is December, with an average of 10.9h of daylight.
In Cozumel, the average sunshine is 6.2h.
Months with the lowest UV index are January and December, with an average maximum UV index of 7. A UV Index reading of 6 to 7 represents a high threat to health from the exposure to the Sun's UV rays for the average person.Note
: The daily maximum UV index of 7 in December interpret into the following advice:
Take precautions against overexposure. Protection against sun damage is needed. Seek shade and minimize exposure to direct Sun in a period between 10 a.m. and 4 p.m. when UV radiation is most intense; keep in mind that shade structures like parasols or canopies do not provide perfect sun protection. On bright days sunglasses that block both UVA and UVB rays should be worn. A hat with a wide brim is extremely helpful, as it can prevent roughly 50% of UV radiation from reaching the eyes. Beware! The reflection of water and sand dramatically increases exposure to the UV rays.