Chickens have a natural laying cycle that peaks in the spring and troughs in the fall. The typical flock is at its worst in November, and actually lays better in the depths of winter.
By early spring, long before the weather is nice or the supply of natural food has increased much, the hens start laying like crazy. It’s not about temperature and it’s not about food: it’s about natural cycles. The hens lay their eggs before the food supply is very good because it’s the growing chicks who need easy pickings, not the broody hen, who hardly eats anything when she’s incubating her eggs, anyway. So the natural egg-laying season has to happen before the time of plenty.
In the fall, the pickings are still pretty easy, but what would baby chicks eat during the upcoming season of scarcity? So the natural tendency is for egg-laying to cease.
This means that Thanksgiving is an unlikely time to feature egg-based dishes, while Easter is a great time. Similarly, farm flocks are thinned in the fall so that only the most valuable animals are kept over the winter, so it’s a good time for a turkey dinner. At Easter, it would be madness to slaughter turkeys, because the whole point of keeping your remaining turkeys over the winter was so they’d lay hatching eggs in the spring, and Easter happens before this is truly under way.
I get emails from people every November, wondering why their hens stopped laying, and what they can do about it. This is one of those problems where anything you do will work, because the rate of lay will pick up in a couple of months even if you don’t do anything. But giving the hens all the chicken feed they want, housing them in an area that’s reasonably dry and more or less out of the wind, and preventing predators, pets, and children from hassling them will help.
The natural tendency for the number of eggs to increase right through the winter is another piece of evidence that, whatever their origins, chickens aren’t tropical birds anymore. They’re far more winter-hardy than most people give them credit for.