, like December
, in Cozumel
, is a moderately hot winter month, with temperature in the range of an average high of 28.6°C (83.5°F) and an average low of 19.4°C (66.9°F).
The coldest months are January and December, with an average high-temperature of 28.6°C (83.5°F).
The average heat index is estimated at a tropical 34°C (93.2°F). Take extra precautions, as heat cramps and heat exhaustion are possible. Sustained activity may result in heatstroke.
Take into consideration that the heat index values are calculated for shade and light wind conditions. With exposure to direct sunlight, the heat index may be increased by up to 15 Fahrenheit (8 Celsius) degrees.Note
: The heat index, also known as 'real feel', 'apparent temperature', 'feels like', or 'felt air temperature', is a calculated temperature value of how hot it feels when the moisture in the air is factored in. Additional factors like metabolic differences, pregnancy, wind, and activity influence one's weather impression. Be aware that direct exposure to sunlight increases heat impact and may raise the 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 is 82%.
In Cozumel, during January, the rain falls for 8.7 days and regularly aggregates up to 81.4mm (3.2") of precipitation. Throughout the year, there are 119.9 rainfall days, and 1489.9mm (58.66") of precipitation is accumulated.
In Cozumel, the average seawater temperature is 27°C (80.6°F).Note
: For any water activity, surface water temperatures between 25°C (77°F) and 29°C (84.2°F) are considered as excellent and extremely pleasant for lengthened periods.
The average length of the day in January is 11.1h.
The average sunshine in Cozumel is 6.4h.
January and December, with an average maximum UV index of 7, are months with the lowest UV index in Cozumel. A UV Index value of 6 to 7 symbolizes a high health hazard from the exposure to the Sun's UV radiation for the ordinary person.Note
: The daily maximum UV index of 7 in January interpret into the following advice:
Take precautions and utilize sun safety practices. Protection against the skin and eye damage is required. The Sun's UV radiation is most powerful between 10 a.m. and 4 p.m. To the extent possible, limit exposure to the direct sun during these hours. 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.