Looking at flying in around the 20th. I'll be walking between hotel, clinic and pharmacy a fair bit and I really don't want to be standing around in the cold while puffy. Is it proper winter by then or still autumn-jacket weather? And is the air quality thing a real issue that time of year?
Usually that awkward in-between. Daytime can be fine in a decent coat, mornings and evenings get properly cold, and some years there's a sudden cold snap late in the month. Pack layers plus a hat/scarf you can pull up. Fine dust (misemeonji) tends to be worse in late winter/spring, but check an air quality app each morning anyway. Loads of locals wear masks on bad days, which is handy if you're feeling self-conscious.
coming from manchester i assumed it'd be similar. it is not. it's a dry cold. lip balm in every pocket