A story on fluctuating temperature and how flexible these eggs can be. I set 6 dozen eggs for a friend in my GQF large cabinet style incubator. It is totally automatic and just need water added for the humidity and temperature checked if needed. It also has back up thermostats etc.So it is really pretty safe. We were going to be gone so I set it in my storage building so my neighbor could come while we were gone and add more water and check temperature while we were gone. We were gone 10 days and when I returned he came down and told me that the temperatures were so cool that the incubator was not able to heat up enough. He said he finally brought a piece of insulation and put over it and that seemed to help. The temps we know did not get about 92-93 degrees for 3-4 days. The eggs still hatched but hatched out 5-6 days late. We still had 55 chicks out of 70 eggs. The chicks did not seem weak . None died in the shell. In fact the ones that were fertile and died looked like they died with in week one of the hatch. My neighbor was shocked at how many chicks he had. I called him and said come pick up your chicks. He said what chicks. I said about fifty chicks. They were RIR, Wh Leg, and Barnyard MIX. He was super happy about those chicks.
This shows how flexible those eggs are, they were able to continue to develop longer because the temperatures were not high enough . It basically delayed the hatch..
Mother Nature!