Gueydan, Louisiana is a small town located in Vermilion Parish. The climate in this area is humid subtropical, with hot summers and mild winters. The hydrology constituents of Gueydan include the Mermentau River and various bayous and swamps. Outdoor recreation opportunities in the area include hunting and fishing in the many wetlands and waterways, as well as bird watching at the nearby Lacassine National Wildlife Refuge. Gueydan is also home to the annual Duck Festival, which celebrates the town's heritage as a prime duck hunting destination.