I am guessing you mean out doors, where I live no dog should be left out doors in the winter ever it is too cold and every year some owner thinks all that fur will keep them warm and the dog dies, last year a dog actually was frozen to the cement it was sad and there was alot of outrage over it.
in the summer generally if you provide fresh water every day that stays cool and plenty of shade then your pet will be fine, maybe not comfortable but will be okay. we have misters in the shade set up for ours and I give them fresh water 3 times per day and add ice to it to keep it cool.
There are breeds that do better than others in different types of weather, the best thing to do is research the breed you have or want and see what the history is, where do they come from? what do they tolerate well.
at 2:45 AM on Oct. 10, 2009