Don't think that because it's getting warmer, that cat parasites diminish. Let's face it, our feline are very inquisitive and enjoy interacting with other cats. Unfortunately these interventions create health risks.
One of the main concerns with cats socializing and coming into close proximity with other animal's feces is worms. Cat worms are easily transmitted through the feces of other cats. It is a difficult situation to avoid, as cats are notorious wanderers, and enjoy socializing as well.
Cat owners have little they can do in the way of prevention if their cat is an outdoors type cat. I have many friends who have cats, and they tell me that they have tried just about everything to keep their cats inside their yards. Unfortunately, most of these cats have wandered out, and developed a form of feline parasites that can be damaging to your cats overall health.