I saw this today and was frankly a bit perplexed. There's a saying up here: "The Arctic favors men and dogs and frowns on women and horses." If I followed this, I'd never walk my dog. In fact, I see a lot of people up here who skijor (cross-country sled while being pulled by a dog) or run with their dogs or do stuff with their dogs when it is way colder than this. The Yukon Quest is run at temperatures way below this.
I would not let a short hair Chihuahua out at those temperatures but that's not a good dog for up here anyway. Dogs that size are eagle bait. Literally. But I've got an Aussie shepherd/mastiff pup who's about 5 months old and about 35 pounds.
We've had a rash of early cold weather so 10 has been about the high for the last week and a half and yet I go walk the dog or let the dog out. Last night I walked the dog at about -5. We were out for about 30 minutes and he did just fine. Ran up and down the trail.
What do you all say? Is it me? Or is this chart too restrictive?