Humidit when they start hatching?

[Soonerguy33]

What should the humidity and temperature be when they start hatching?

 

[Tuffoldhen]

For the last 3 days meaning day 18 thru 21, your humidity levels should be in a range of 60 to 70%, somewhere in there. Now when they do start their pips the humidity goes up anyway so don't worry. It's just natural moisture coming from the wet chick in the shell.