It is my experience that, without exception, predators will find your flock. And once you witness that heartbreak you will do whatever you need to to protect them.
I would have to say your experience may be on the slim side as there are many, many exceptions to your experience. My pop door stays open 24/7, 365...and, no, I don't have a protected Ft. Knox run either. I don't have any run at all. I do, however, have two of the most reliable and trustworthy dogs patrolling outside that coop each night and day. No predator losses through the pop door in all these years.
The OP is asking about warmth, not predator control, and doesn't appear to need a lesson on what is "safe" for chickens.
In answer to the OPs question, I don't close the pop door all year round though found a reason to do so once this past winter when the snow was blowing into the coop and piling up on my deep litter. But that was only for a day.
I place plastic over the wire mesh windows when it starts to blow cold winds here and drop into the 40s on a regular basis at night.
I would have to say your experience may be on the slim side as there are many, many exceptions to your experience. My pop door stays open 24/7, 365...and, no, I don't have a protected Ft. Knox run either. I don't have any run at all. I do, however, have two of the most reliable and trustworthy dogs patrolling outside that coop each night and day. No predator losses through the pop door in all these years.
The OP is asking about warmth, not predator control, and doesn't appear to need a lesson on what is "safe" for chickens.
In answer to the OPs question, I don't close the pop door all year round though found a reason to do so once this past winter when the snow was blowing into the coop and piling up on my deep litter. But that was only for a day.
I place plastic over the wire mesh windows when it starts to blow cold winds here and drop into the 40s on a regular basis at night.
