I had an electrician run Cat 6 to all the bedrooms in my older house, and he ran the cable all along the outside of the house (not buried). It’s a blue Southwire cable that I believe is rated for indoor use, and I’m worried it may be an issue come winter here in northern-Illinois. Should I be worried about an impending doom and if so what can I do to protect the cables.
If you’re not messing with it (as in, trying to move/bend the cable when it’s icy cold), I don’t think winter is the main issue. I think the main problem with having cables like this outdoors is UV (sunlight) breaking them down, causing the cable jacket to crack, and then you get water ingress. Like in the video here: https://www.reddit.com/r/IndianGaming/comments/lt3u5v/water_droping_from_my_ethernet_cable_i_noticed/
I would replace the outdoor sections of the cable with one that is actually rated for outdoor use, but it will probably be fine to wait until the spring/summer.