I use chickens so i don't know the temperature and humidity. My early ones for some reason take 28 days but they started hatching in 26 a couple weeks ago. The later ones have been hatching in 26 days for the last 15 or 20 years. I have no explanation for it but i know what happens. I have always blamed it on the weather getting hotter and possibly starting to develope a little before i set them but i really don't know for sure.