I wish I could give you an easy answer to this question! One of those “when the temperature is ** degrees, stay inside, wrap up warm and curl up on the sofa and watch trashy films instead of taking your dog out” answers… But it isn’t anywhere near as straightforward as that, so the best I can do is… “it depends”!
What to think about
First of all, it depends on your dog’s breed or type. Some breeds have thick coats with an undercoat and enough body fat to easily cope with lower temperatures – and many even love the cold far more than they enjoy a summer’s day. Others have thin coats and light builds and so can’t cope with even the hint of a draft without feeling the chill and demanding a jumper to even go out for a quick pee.
As a quick rule of thumb, look at the country where your dog’s breed (or breeds) was originally developed, and what they were bred to do there. Was it a cold climate where they were bred to be outdoors and working all day? Or was it in sunnier climes where the most they had to do was be a treasured indoor companion?
To give you an idea, the Siberian Husky, with their thick double coat, was bred to pull sleds all day every day through the harshest snows of the frozen north – and so for them even the coldest UK winter is no challenge whatsoever, and in fact is probably their idea of the perfect day. Whereas, the tiny Italian Greyhound, with their slight build, thin skin and fine coat was bred to be a rather cosseted ladies’ companion in the palaces of the Mediterranean – and so the slightest hint of a chill will see most of them diving under the nearest duvet until spring!
Our most popular breeds in the UK come from the gundog group, and while they might not be quite as extreme as the sled dogs, they were still mostly bred in harsh climates and were developed to work happily and enthusiastically all day every day whatever the weather, and so a snowy day in Swindon isn’t going to cause them any problems whatsoever – in fact they probably won’t even notice!