Sorry to hear about the pain you have in the knee joint when there´s cold weather.
If I don´t wear leggings with some percentage of wool in them or some undergarment with wool, I too experience pain and discomfort in most joints and muscles. In fact as soon as this starts happening, I know the "summer" is over for me and its time to get into those woolies. Even my feet feel "happy" and comfy if I´m wearing woolen socks. Synthetic "stuff" wont do.... my body hates it and starts sweating and stinking! You may have problems finding clothing with some wool in them. In Europe it´s easier, I imagine. They´re easy to buy in Italy. Most grateful to a young, german medical student who told me how she cured her aching joints - she used to suffer from juvenile rheuma.
Give it a try: hoping it may help you some!