How I carry is the same no matter the weather. Definitely much easier to conceal in the colder weather you just need to practice on how your going to make a clean draw.
Good article Killer Ford.
Personally I don't even always carry the same gun during the same season. And I definitely carry different rigs in the winter. Digging a Shield out of an IWB with 3 shirts and a coat on ? Screw that. Basically as soon as I can put a jacket or a flannel on ( excluding at work) I start carrying full size in an OWB.
I rotate similar guns all the time. Occasionally a Sig P365 will be worn on belt or in pocket but usually I prefer a larger gun. On rare occasion a 1911 but here I am not fond of a safety on my EDC. The biggest change is on a rare really cold day here in SC i will drag out my Miami Classic Shoulder Rig for my P226.
OWB during the cool/colder weather, due to wearing coats, and primarirly IWB in warmer months, but I need to increase my button-up, wicking mat'l preferred, untucked shirts. I will go OWB (kydex paddle holster) when fishing locally, but still have a IWB holster handy in the truck.
Like @ScottJ when possible I will carry OWB as I am quicker that way vs IWB and during the colder months a light jacket or flannel shirt helps cover that up.
If I am wearing an untucked shirt of sufficient length, or a jacket, I *always* carry my XDM Compact OWB using a Crossbreed Snapslide holster. I tend to wear those fishing shirts year round, so it works out pretty well for me. If I am going dressier, and tucking the shirt in or not wearing a jacket, then I switch to my Crossbreed Supertuck, or drop down to my Ruger LCP in a Desantis Nemesis or Superfly pocket holster. None of that is seasonal so much as wardrobe choice based.
Right now its the OWB carry option all the time, as I put on some "holiday weight" that is making IWB a bit uncomfortable...
Other than an occasional jacket, my wardrobe doesn't change very much from season to season. Any variance in my daily carry is due more to my destination than the weather. If I am switching from a compact semi-auto carried IWB to a micro or subcompact in the pocket, it is because a business situation or fitness activity will not allow me to discretely conceal my normal weapon. There are also certain destinations where I will not go without a larger firearm, even if this means wearing slightly warmer clothing than I would prefer.
Like Hans, the only significant change I make to my routine is to throw a J-frame in the exterior pocket of a heavy jacket on the few days a year that are cold enough to require one. I will still have my normal carry piece in my waistband, but keep the revolver in the outside jacket pocket to provide immediate access if needed.