Official BYC Poll: What humidity do you use in incubation (first 18 days)?

What humidity do you use in incubation?

  • 30-40%

    Votes: 24 27.6%
  • 40-50%

    Votes: 23 26.4%
  • 50-60%

    Votes: 13 14.9%
  • 60-70%

    Votes: 8 9.2%
  • I have no idea

    Votes: 9 10.3%
  • I don't have an incubator

    Votes: 6 6.9%
  • Whatever humidity my broody wants!

    Votes: 13 14.9%
  • Other (elaborate in a reply below)

    Votes: 7 8.0%

  • Total voters


Life is good...
Premium Feather Member
7 Years
May 16, 2014
Even at lockdown you still don’t add water? Not questioning your process, I just want all the details before I try it. I know you are the guru of incubation!
I am hardly a guru. 🤣
No, I add water at lockdown.
The question was incubation so I didn’t write that part. I add water at day 19 or when I see the first pip, which ever comes first. Around 60% humidity but I find it does not have to be so precise. My own birds’ eggs normally hatch day 20.😊
Edited for spelling
Last edited:


Fuzzy Feather Fanatic
Premium Feather Member
10 Years
Jun 9, 2011
My Coop
My Coop
I answered the poll honestly; I have no idea. I don't even have a hygrometer for my incubators. Never had an issue with just tracking air cell growth and adjusting the vents and amount of water accordingly, even with shipped eggs. That's one less thing to constantly fret over when I've got eggs in the incubator. 🤣


In the Brooder
Apr 23, 2021
I don’t add any water during the first 18 days so it’s around 30-40%

During lockdown I add water so it’s 50-60% and once they start pipping the humidity increases to around 70%

I have had every fertile egg that I’ve incubated hatch doing this


8 Years
Aug 27, 2013
My little piece of heaven!
My Coop
My Coop
Humidity inside the incubator controls the moisture loss inside the egg. Almost every bird egg needs to lose a certain percentage of weight/moisture for the bird to develop properly and hatch. This is accomplished through pores in the eggshell. Humidity affects how quickly this moisture evaporates through those pores.

Humidity too low can cause too much moisture loss, the air cells may get too large, the chick can get crowded, and can have a difficult time hatching. If humidity is too high, and not enough moisture is lost, then the air cells can’t grow enough, and chicks can drown; or chicks can grow too large to be able to maneuver and hatch, or there isn’t enough air in the cell for the chick to use to complete its cycle and emerge.

It’s not really rocket science for incubation purposes, and there is some flexibility, but too much to one extreme will usually cause problems. So this week we would like to know: What humidity do you use in incubation (first 18 days)?

Place your vote above, and please elaborate in a reply below if you chose "Other".

View attachment 2881719

Further Reading:

The Beginner's Guide to Incubation
Incubation Cheat Sheet
Incubation Humidity

(Check out more exciting Official BYC Polls HERE!)
Dry incubation.


Sep 10, 2021
I aim for 35% now, although I've tried dry hatches that went as low as 16-25% with no noticeable losses!

I just got a big cabinet incubator and plan to do split hatches with 1/4 of the eggs hatching out every week, so I might experiment with keeping everything a consistent 55-60% 24/7. I'm not sure if it's going to work out better or worse than constantly alternating low/high humidity.


Jan 26, 2020
All my chicks are hatched au naturel. Our belief is that mamas know better than us when it comes to hatching chickens.

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