disappointed in the girls today - 4 eggs out of 5 barred rocks, 5 welsummers and one white jersey giant. It went up to 14 today after having lows of around -25 most of the week. I have lights on for 13.5 hours a day and the coop does have a small heater to keep it just above freezing at nest box height. They averaged 8 eggs a day, just like usual, all through the week when coop temps were around 10 to 12. I did clean out the coop this afternoon so maybe that threw a few of them off. I don't think temps matter very much.