Why do they molt in the fall?

[PaintedMeadows]

Why do chickens molt in the fall? Do they grow warmer feathers? Is it so there are no damaged feathers to let the cold air in? Is it to line their coop with warm fluffy feathers? curious about this.

 

[keljonma]

In our flock, the earliest starts molting in late August and the entire flock seems to be done with molt by the end of October.

 

[PaintedMeadows]

I'm curious as to why. Is it linked to what time of year they were born? Is it the weather? The temperatures? The amount of light? Curious.