I live in Houston, and the humidity here is high year-round. I think there's nothing special to do if you live with high humidity, except be thankful. I've been trying to use a Hovabator (the kind with the wafer). I started with 10 eggs and was kind of all over the place with the humidity - started at 45-50 and let it get dryer - down to 25, then upped it to 75 on day 20. (Yeah, yikes!) Yesterday I had 2 hatch, and today one more plus one pipped egg. I hope more chicks hatch as these are blue Marans, an expensive experimental hatch, but next time I am using a Genesis and keeping this incubator for a short-term brooder. The woman who sold me the eggs hatches dozens of eggs a month and told me to keep a towel on top of the incubator to hold humidity in.