I've run my Janoel 12 3 times this year and every time, every egg has hatched. Here is the thing....I keep forgetting to adjust the humidity. I've added water...but since its on a different menu and I always forget the lettering I never get to it. It just stays with the default...and I'm still having super success. So I wouldn't worry about slight changes in temperature. I'm sure a hen isn't checking her sweat level to the nearest % point.