Cadiz is one of the easiest Andalusian cities to enjoy with a dog: small, walkable and open to pets on terraces, in green spaces and, in season, on the beach. Two things shape your trip the most: the summer heat and asphalt risk, and the seasonal beach calendar.
From June to September, Andalusian asphalt and sand can reach 50-60C between roughly 11:00 and 19:00, hot enough to burn paw pads in seconds. Walk your dog early morning or after sunset, test the ground with the back of your hand, stick to shade, and always carry water. The Atlantic breeze keeps Cadiz cooler than inland Andalusia, but the paw-burn risk is still real.
City beaches (La Victoria, Santa Maria del Mar, Cortadura, La Caleta) only allow dogs out of bathing season, roughly 1 October to Palm Sunday. In summer the only legal spot for a dog on the sand is the dedicated Torregorda dog beach at the end of Cortadura. Bringing a dog onto a main beach in July or August can mean a fine, so plan around the calendar.
Dogs must be leashed in all public spaces in Cadiz, and dogs over 20 kg must wear a muzzle in the street. Off-leash running is only allowed inside the fenced areas caninas. Always carry waste bags, as municipal fines apply for not picking up.