In the Cenotes of Riviera Maya and Tulum you' ll find that there is fresh and salt water, these waters are not mixing, they are just siting one on top of the other called Halocline. They remain separated by the difference of density between both waters. As light is transported at different speeds by the difference of density between the water which produces a refraction of the light which is observed like snorkeling with a foggy mask.
Temperature of the Water in the Cenotes:
Fresh water 25° C / 78 ° F.
Salt Water 26° C/ 79° F.
These temperatures are constat throughout the year, wich varies is the external temperature.The climate in the Mayan Riviera is subtropical and counts as one of the places with highest proportions of sunny days in the world.
The temperature average during the year is at about 25,5°C/ 79°F.During the summer months June to September the temperature reaches a maximum of 40°C/104°F with an average at 30°C/86°F, during the winter, December to March the temperatures can get as high as 35°C/95°F and drop down to 15°C/59°F during very few days.The best hours to enjoy the Cenotes for Snorkeling are during the morning hours until 5pm.During this hours the sun light iluminates the Cenotes producing the most unique light effects in the World. Sunblok lotions and products against mosquitos are not allowed since the chemicals agents affect the sensible environment of the Cenotes.