What causes an early hatch?

[emjay]

Well, I had no restraint. I set a 3rd batch in the incubator. Put in 41 eggs. Lockdown was June 17th at 7:20 pm. Eggs started hatching early afternoon today. 2 have hatched so far, and one more is fully zipped. What causes such an early hatch? They weren't due until the 20th.
My temps were at 101, the whole time, and humidity was in the high 20's.

The eggs are zipping quite fast.
They are wanting out in a hurry. !!!!!!

 

[panner123]

High temps will cause early hatch. Other than that a miscalulation of days.

 

[emjay]

definitely not miscalculation. so...perhaps my thermometer is slightly off. As the last two batches were at same temp, and hatches were right on schedule.

I guess the main thing is that they are coming out nice and healthy, so I'm pleased.

3 out so far, one more zipping away.

 

[cmom]

I think a high temperature can cause an early hatch. Also, If your eggs were stored in a warm area before being placed in the incubator can also cause an early hatch. I keep my incubator between 99.5 and 100.