Long read, short: in my opinion, if your dog is uncomfortable and the problem can be fixed with clothing, it probably should be. Every breed and even every individual is different. If your dog's level of comfort could be improved by clothing, I see no harm in clothing your dog even when it is not strictly necessary.
This, for whatever the reason, is a contentious issue. Whether people should clothe their dogs or not always seems to draw heated opinions from every side. I admit, before I brought Argos home, I was extremely skeptical that any dogs needed clothing, it was just a fashion statement. Sure, hairless dogs could use clothing, I supposed. I guess if you live in Alaska or something jackets might be necessary. But the whole thing just seemed rather unnecessary.
Then I brought Argos home and I realized how easily my small sighthound mix got cold. So I bought him a sweater. Immediately his comfort level increased. And then the sweater soaked through while we were out in the rain. And I bought him a rain jacket. And those two layers worked great until years later we started getting over a foot of snow on a more than annual basis, and I got him a winter jacket.
When I later added Ash, I just went ahead and bought him a couple sweaters and a coat. I didn't fight the process. And when I first got Ash our winters were still quite mild. A simple sweater or jacket was usually enough. But there's been a major climate shift in the past half decade in our area. Before a handful of years ago I had almost never seen single digit temperatures or more than a couple of inches of snow in a year. There were some years it hardly ever dropped below freezing or snowed at all.
Six weeks after I brought Amidi home, we received over 39" of snow over the course of 72 hours. And since then our winters have been a scale of magnitude harsher. Temperatures have been colder. Snowfall has been deeper and more frequent. So I finally started leaving vest and pajamas on my dogs while they were in the house. Both Whitman and I would love to keep our house at 65*, which is much too cold for the Azawakh to be comfortable, so we compromise and keep the house at 70*. And in winter it frequently dips below that because our heater is inconsistent, so it became practical to ensure our dogs were comfortable.
Over time we developed a wardrobe for each of our dogs:
Single layer fleece vest
Single layer legged fleece pajama
Double layer fleece coat
Heavy winter coat
Snow suit (4 legged)
Reflective hunting coat
So when adding a new short coated sighthound I start accumulating the above clothing for each dog.
Is that too much clothing? Maybe for some areas. Definitely for some climates. However for the very variable, increasingly less temperate Pacific Northwest? It's prefect.
We use the vest mostly in spring and fall when they are more comfortable with a light layer. The pajamas are perfect for lounging around the house. Whitman and I both prefer to keep the house under 70* and that's generally too cold for my dogs to be truly happy. It's easy enough to just throw pajamas on them and the dogs will even ask for them (go to where they're kept) when they're too cold. You can see them shift from a small ball to sprawled comfortably within a few minutes.
The double layer fleece coats are our most used. They are great for most of winter and I can always layer them if I need to. I layer these often with their rain coats when it's not too cold out but I don't want the dogs to get soaked through. While I haven't yet, I'll even buy Azhidar a rain coat at some point. Does he need it? No, not ever. But dog clothes aren't just for dogs' convenience, they can also be useful to people. I don't want to always deal with a soaked coated dog. A rain coat helps with that. Sometimes when I just have Azhidar out, I borrow one of the other dog's raincoats for him for my own convenience.
Their heavy coats didn't get a lot of use until a few years ago, but our winters have been notably colder and when I need something both warm and waterproof these are perfect. I actually added the snow suits this year since we routinely get more than a foot of snow multiple times a year. I had the chance to use them for the first time last week and they made a huge difference in making sure the snow didn't splash up their legs and make them cold.
The hunting coats thankfully I don't need very often. None of the trails I hike regularly allow hunting. But when we travel or hike different trails, they are an important safety factor. I've also found with a brindle dog, he tends to blend into the woods, so it helps me find Azhidar quickly at a distance (the entire point of the jacket).
And lastly the cooling coats. I don't use them often. I have a desert breed. Mostly I use them when my dogs are running sports in 90+* weather and it's not too humid (otherwise evaporative cooling doesn't work). In contrast, when I have Oliver the Newfy or other coated breeds or with Azhidar in the coming summer, I anticipate using cooling coats on days the Azawakh would never need them. The other time I'll use them is when we have an unusually hot day in the midst of much cooler weather. For instance, in the picture it had been in the low 50s the whole week and then that day was in the mid-80's. My dogs weren't adapted to suddenly warm weather so even the Azawakh and Saluki got very warm.
And I think that's something to keep in mind. I know plenty of Azawakh live in Scandinavia. And often I see them out in the snow with no coats in temperatures that my own dogs would struggle in. The reason for that is not because those dogs are inherently tougher or because mine are babies about the weather. It is because they have adapted to cold weather through repeated exposure, whereas mine have not. As winter progresses, my dogs don't need as heavy of clothing even in much cold temperatures than early fall, because they have gotten used to the cold. It's why even my desert dogs would need a cooling coat on the day I described above. Desensitization and habituation are things that happen over time. For instance, Gem is struggling in our colder climate. Whereas my dogs who got to experience the gradual change in weather, Gem was taken from warmer Tennessee weather an thrown into the mid-30s weather.
I think another place where people struggle with clothing is the fact that this is going to vary by breed and even individual. When I bring board and train dogs to racing in summer, I have to keep in mind usually their temperature needs are very different than mine. When I have heavily coated breeds that even more prone to overheating my precautions change even more - aluminet over a crate, multiple fans, maybe a misting fan, cooling mats, cooling coats, spraying them down, etc. All of which I rarely need with my personal dogs.
Likewise, in heavy winter my smooth coated dogs need the coats. Whereas even as a 6 month old puppy, Azhidar does not. In fact, he loves just lying out in the snow and rain. But I frequently get people who are aghast that I haven't put a coat on him, even though he'd never want one. Meanwhile my Azawakh would literally get hypothermia without them. In February 2021, we had a snow storm where we got over a foot of snow. I had two board and train dogs, one was a
Staffordshire Bull Terrier mix who was staying and one was a Golden Retriever who was supposed to go home but couldn't until the roads were better. I walked them down into town as part of a training session. I threw a light coat on the Golden and she shook it off twice before I left it at home. She loved the snow and would happily lay in it and never got too cold. Meanwhile the short-coated Staffy mix was freezing and borrowed my dogs heavy winter coat plus his sweater plus my dog's boots and he still got a bit cold.
To me, dog clothing are tools. If my dog is uncomfortable I often can't accomplish my own goals whether that be a house with an ambient temperature of 68* or a hike in the rain or the snow. So I apply a tool to the problem to solve it. The type and amount of clothing needed will vary by individual.
One final note- I have zero problem if you want to dress your dog up because it's cute. As long as it's not doing them any harm, your dog, do as you wish (and share pics).