You're not doing anything with minTemp and maxTemp. If you intend to, you'll probably need to keep separate readings for each incubator - another array. Do you plan to use the humidity data to control anything or is it just a display item?
Consider using an SD shield so you can log your data. If you have a bug in your code, it may help to detect what's happening. Also, some kind of alarm functionality would be nice. When the bulb fails, you likely don't have much time to replace it before a batch of eggs is lost.