Q: Why are my hens molting so late, when it's cold, and how can I help them stay warm?
A: Chickens molt annually, and some chickens do molt later than others. Often this varies by breed as well as the conditions under which they live.
Some birds start at the end of August or beginning of September, while other breeds may wait until November or even the beginning of December. Your chickens begin molting when their bodies tell them it is time, and that is usually based on daylight hours. Decreasing day length is the normal trigger.
Do you add light to their coop? Some people add light to try to keep their birds laying more consistently year round, but this can throw off your birds' natural cycle. Eventually, their bodies will tell them to lose their feathers anyway, but if it is not based on the usual triggers, it can come at an odd or inconvenient time. If you don't add light, stresses caused by a temporary shortage of water (like frozen water), temporary shortages of feed, or other things can trigger a molt if your flock hasn't molted at the regular time of year. If you add light, that might have caused them to wait until it's very cold.
Late winter could certainly be problematic if you live in a very cold area, especially if your girls are going through a "hard molt" rather than a "soft molt." With a hard molt, a chicken can lose most of her feathers all at once, which would leave her very cold. Typically, we recommend that if you choose to add light to the coop, you wait until after your flock's annual molt to do so. Waiting until after the molt to add light will mean they'll get the cues to molt on schedule rather than late when it's especially cold.
If you have a chicken saddle, apron, or something similar, you might use it to give your late-molting girls a layer of protection when it is very cold outside and they are lacking in backside feathers. We sell saddles or aprons on our website.