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 best time of year to travel to Cancun (weather-wise) is during the dry season's coolest months: January and February. March and April are the driest months of the year, and also the sunniest months in Cancun. Humidity is high in Cancun, often around 80%. April and May have the lowest humidity.