hi rain and thanks for your post, There is no set temperature which a puppy cannot stand. There are many different factors that can affect how your dog reacts to low temperatures but in general it is really important for your dog to have access to good shelter such as a good warm kennel with warm dry blankets. If temperatures are getting below about 10 degrees celsius you should consider getting your puppy a warm jacket or jersey. You can also try microwavable pet heat pads in your puppies kennel to keep off the chill. When you get your puppy out of bed in the morning check his blankets and make sure they are not too cold or even frozen, also check that your puppy himself is not too cold, remember that it is normal for his extremities such as feet and ears to be chilly in cold weather but his body especially under his belly should be warm.
I hope this helps, enjoy your new puppy and if you have any further questions please don't hesitate to ask.
