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.
I was in cancun in April and have been to cancun in Janaury and June and November and April was my favorite. It was about 31 degrees celcius everyday, if it did rain it only lasted a few minutes. I loved the weather, not too hot or too cold.