Effects of high humidity. Humidity is considered too high when its level goes above 45% - 50%, sometimes as high as 80% and up. High humidity can be especially dangerous when combined with high temperature - as mentioned above, high humidity disrupts the body's ability to cool itself, which may lead to a heat stroke.
The average sea surface temperature in April 2017 for Cancun was 84.0Â°F. The maximum and minimum values were 83.0Â°F and 85.4Â°F respectively.
The average temperature in Cancun is 80F (26C). January and February are the coolest months; June and July are the hottest. Cancun Weather. Even though the temperature does not vary that much throughout the year, there are 2 distinct seasons in Cancun. The wet (rainy) season is May to October and it is slightly hotter.