We had an early snowfall in Western Washington this year. It started snowing yesterday, while the hens were out pecking for bugs, and they were not very amused by the whole ordeal - this was their first experience with snow. They don't seem to mind the rain that much, but the snow made them pretty nervous.
There was a fair amount of snow accumulation overnight, and the snow is continuing to build up during the day. When I opened up the girls' henhouse door this morning, Penny popped her head out briefly to assess the situation and decided that it was a good day to stay indoors.
Their water had frozen, so I filled the jug with warm water and placed it and their feeder inside the henhouse. I also put a tarp over their yard to help trap heat and keep the snow from building up in their pen.
Chickens can do just fine in a snowy climate, as long as they have a dry shelter where they can get out of the wind and the snow. The bedding inside the coop provides some extra insulation, and the snow that piles up on the roof also helps to keep heat from escaping. If the weather gets too far below freezing, we might bring them inside the garage to keep them warm.
The biggest issue is the water situation. Their waterer should be checked periodically to make sure that it hasn't frozen. As I mentioned, we fill our jug with warm water to deal with that problem. You can also purchase water heaters; GardenSphere, on N. Proctor in Tacoma, sells an electric heater base. A variety of heated waterers are also available at shopthecoop.com.
It's also important to keep an eye on their wattles and combs, as these areas are likely to be affected by frostbite. Rubbing petroleum jelly on the wattles and combs can help.
More reading: