The town is situated in the west of the
département, between
Notre-Dame-de-Monts and
Saint-Hilaire-de-Riez. It is split in two by a long plantation of
pine trees, stretching from north to south along the coast. The
centre-ville lies to the east of the cordon, while the seafront forms a center to the west. Saint-Jean-de-Monts is known for its sandy beach, which is more than eight kilometres long. Due to its often low tides, it offers a great area for walkers, fishermen, and beach games. The town is noteworthy for the recent restoration of its seafront, a town planning operation that took over five years to complete. The result now means a network of footpaths and cycle tracks are enhanced by plants, flowers and shrubs. The predominantly flat terrain has allowed for the development of a vast 500 km2 network of
cyclepaths, known as the
Sentiers Cyclables de la Vendée. These paths stretch from the island of
Noirmoutier in the north, south past
Saint-Gilles-Croix-de-Vie.
Climate Saint-Jean-de-Monts has an
oceanic climate (
Köppen climate classification Cfb) closely bordering on a
warm-summer Mediterranean climate (
Csb). The average annual temperature in Saint-Jean-de-Monts is . The average annual rainfall is with November as the wettest month. The temperatures are highest on average in July, at around , and lowest in January, at around . The highest temperature ever recorded in Saint-Jean-de-Monts was on 27 June 2019; the coldest temperature ever recorded was on 16 January 1985. {{Weather box|width=auto ==History==