Humidity Levels


10 Years
Apr 21, 2009
Im wondering on average what humidity level do you guys use while hatching ducks eggs. The more i read the bigger the range in varations i seem to get it goes from anywhere from 30 % up to 85 percent before lockdown. Is there something im missing for it to be that huge of a gap or in the end does it not really affect the hatch that much anyhow? Im not using a wetbulb i have a hydrometer so what level would you guys reccomend i run the humidity to for ducks eggs?
Humidity levels will be all over the map.

Just depends on what works best for the particular situation.

I tend to stay away from humigity too high during the first 18 days (anything over 50 is too high for my situation).
I've ended up with drowned chicks with high humidity.

I keep mine in the 40's.

There are others who do a dry incubation and keep the humidity level in the 20's.

If this is your first hatching experience, I would go with what the instructions say on your incubator and test from there with each subsequent hatch.
Consider using a "dry incubation" where no water at all is added except at lockdown. During lockdown, I like humidity around 60-70%. My humidity during the days prior to lockdown is between 20-30% and I have great hatches.
Are we talking that low of humidity for ducks aswell? I know i incubate chicken eggs at 60 % before lockdown and bump it up to 65 or 70 and all my hatches havent been a issue.
Im a little confused about humidity anyhow. Whats the difference between relaitive humidity and what you measure on a wetbulb. Lets say for example im using a hydrometer what read should i have for ducks eggs in the incubator. I think this where the vast numbers come from talk about one to the other on different post. I know this confuses me it must someone else out there so a answer would help a few of us.
Humidity expressed as a percentage is a straight up percentage of moisture in the air. Humidity expressed as a wetbulb reading is an indication of how fast evaporation will occur, which will be quicker in drier conditions and slower in more humid conditions. Basically you're measuring the same thing but expressing it differently. but I don't think the huge differences in humidity used by some people are down to confusions between wetbulb readings and percentage humidity. People get success with a huge variety of humidities, and there's not really a one-figure-fits-all number the way there is with temperature.

If you incubate chicken eggs in 60% humidity days 1-18 then you're in the extreme minority. Either that or your hygrometer/wetbulb thermometer isn't accurate! (Seriously, have you calibrated your instruments? Always a good idea...) Most people using humidity that high would end up over-humidifying their eggs and drowning their chicks. Bearing that in mind, you should be careful of taking other peoples' advice about what humidities to use for duck eggs, cause what works for them may well absolutely not work for you at all.

Having said that, here are some numbers to think on...

Chicken eggs should lose 13% of their starting weight by lockdown. Waterfowl eggs should lose 15% of their starting weight by lockdown. While duck eggs need to lose slightly more moisture, they have a longer incubation period to do it in, so moisture loss rates will be roughly equal. Loads of people recommend that you incubate duck eggs in a much higher humidity than you use for chicken eggs, but I weigh all my hatching eggs to calculate correct moisture loss, and any time I've incubated duck eggs I've found that they actually require a very slightly lower humidity than what I usually use for chicken eggs.

However they DO require a higher humidity for lockdown and hatching. Most recommendations for ducks are 80%+ humidity for hatching, and I definitely noticed that the one time my humidity dropped to 75%, my last duckling struggled for quite a while to get out. I think duck egg membranes are a lot tougher than chicken eggs and can dry out more quickly.

Hope that info might be of some help to you!
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That does help quite a bit thank you thats the clearest answer i have been able to find on the issue it makes total sense.

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