I have a husky who spends 90% of the time outside. It's only the start of January, and he's already shedding like it's March. He didn't do this last year. Why would he be full on shedding like this so early?
All I can say is there is no rhyme or reason to it and that it happens. We have a dog that is "shedding" recently too, but it has been a real mild winter so far. Sometimes she will grow in a new underfur before winter is out and shed again in summer. Brushing seems to get it out faster and allow new underfur to grow in. I imagine there could be some other causes too...just saying we've seen it happen a bit and so it isn't all that unusual.