Hot? Check. Arid? Check. Home to lots of retired people with nothing but time on their hands? Triple check. Phoenix's warm and dry climate is great for canine companions, but the city's retiree population is even better for trips to the dog park. With 85 percent of days free of rain, there's only a 15 percent chance a dog's owner will cry rain as an excuse. Just be sure to keep your panting doggy hydrated.