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.
Winter Weather in Cancun. Winter temperatures range from average lows of 21Â°C (70Â°F) in December, January and February (the coldest months of the year) up to average highs of 28Â°C (82Â°F) for the first two months and 29Â°C (84Â°F) in February.