Most hens will stop laying in winter as the days get shorter. A lot of people believe it is due to cold weather, but it is usually because they are not getting enough daylight. Laying hens need 12-14 hours of light to keep up optimal production, we're getting 9 hours of natural light (at least here in Kansas). You'll probably want to add supplemental light to keep them laying through the winter.
It is recommended you use one 40 watt bulb for every 100 sq ft of coop space, or one 60 watt bulb for 200 sq ft. The lights should be suspended
at least 7 feet off the ground to prevent fires. I also recommend you get a guard of some sort, so that a flying chicken can't break the bulb or knock it to the floor. And make sure to regularly check that there's no cobwebs, dirt, dust, straw, etc. around the guard, that could start a fire.
I have a 60 watt bulb on a timer in my coop. It comes on a couple hours before the sun rises, goes off, then comes on a couple hours after the sun sets in the evening. My hens keep up fairly normal production in the winter, except when they're molting of course.
Best of luck,
~~Ms. B
