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.
Cancun Weather in April: Itâs a dry month in April with the lowest precipitation rate of the year at 27mm. The high temperature and the low temperature both continue to increase and range between 90Â°F (32Â°C) and 73Â°F (23Â°C). In May, the average high temperature increases a single degree to 91Â°F (33Â°C).