It's entirely possible to have fun with French Bulldogs in the summer if you take into consideration some of the breeds special health needs.
French Bulldogs are a Brachycephalic i.e. short-faced breed. The shorter breathing system puts them at a very strong risk for heat stroke. The Shorter airway=less possibility of cooling the air which the dogs draws into its body. Dogs do not sweat. Their only means of reducing built-up body heat is by panting.
The leading cause of heat exhaustion, and its advancing into heat stroke; is leaving a dog in a hot car. Even on a mild day (75-80 degrees F), the temperature inside a car can raise up to 130 degrees rather quickly. Leaving a window slightly open will not prevent heat buildup. Leaving a dog in a car on a warm day is a risk to the dog's life. Remember this saying - "Cars can kill in warm weather". DO NOT leave your French Bulldog in a car.
Most French Bulldogs have no natural buoyancy in water
and will sink like a rock.
Frenchies are NOT swimmers, and can easily drown in even a decorative pond in the garden. Less obvious is the danger posed by swimming pools with covers. In too many instances, adventuresome Frenchies have managed to crawl under a swimming pool cover and drown because no one sees them struggling to stay afloat. It's probably a good idea to supervise your Frenchie closely around water and not allow him or her into the pool's deep end.