Climate
The Mediterranean climate is characterized by long, hot summers and cool, dry winters, with few days of frost, but even in the garrigues, winters are colder. As soon as you reach the Cévennes and approach Mont Lozère, summers are shorter and more temperate, and winters can be harsh depending on altitude. From June to September, daily temperatures rise above 25°C during the day, and exceed 30°C at the height of summer, while rain is rare and only falls in sudden thunderstorms. While in the south of the département, the minimum night-time temperature rarely drops below 17°C at this time of year, it's sometimes a good idea to cover your shoulders in the evening when you're further north.
Nevertheless, the region enjoys 2,700 hours of sunshine a year, compared with a national average of less than 2,000 hours. Mediterranean rainfall is infrequent but abundant. A 100-millimetre rainfall in a single day is not exceptional, and 200-300 millimetres can easily fall in two or three days in spring and autumn, the two main rainy seasons in the Midi. In the southern garrigues, annual rainfall varies between 700 and 800 millimetres, rising to 1000 millimetres towards Alès. In the Cévennes, annual rainfall ranges from 1,300 to 1,700 millimetres.
While meteorologists are baffled by the layout of the mountains in the Cévennes foothills, with the orientation of each valley and its exposure completely changing the climatic data, no mountain escapes the phenomenon of "Cévennes episodes", generally around the equinoxes. Powerful winds and strong thunderstorms, the violence of the rainfall causes sudden and devastating floods, notably those of the Gardons known as "gardonnades". The intensity of these episodes can last for two or three days, during which time all you can do is wait in a sheltered spot, and hope the damage isn't too extensive..
The "ven", or south wind, is mild and humid, bringing clouds from the Mediterranean. When it blows from the southeast, it's called "le grec", "le marin de Beaucaire" or "vent de miejour" in the mountains. The mistral, "mistraou" or "maestral", which comes from the north down the Rhone valley, can be very cold, but it's the mistral that blows the clouds away. The tramontane, which arrives from the west and blows between the Pyrenees and the southern Massif Central, is called "trabès", "traverse", "roudergue", "l'auvergnat" or "narbouné". The easterly wind, "l'aigalas" or "ajalas", is feared in winter and comes with a somewhat overrated reputation as a tireless blower. The proverbial Aigalas bouffo es pas jamaïs las means "the aigalas blows and is never weary".
Characteristic landforms and landscapes
The Camargue
The south of the department is composed of agricultural areas, marshes and a small but beautiful coastline of 23 km along the Mediterranean, and on either side the Hérault and Bouches-du-Rhône. Vauvert, Saint-Gilles, Le Grau-du-Roi, Aigues-Mortes and Port-Camargue have an authentic charm that has nothing to envy the neighboring La Grande-Motte or Saintes-Maries-de-la-Mer. The tip of Espiguette, a dune beach 10 km long and 2 to 4 km wide, serves as a border between the ponds and the Mediterranean. It is the plain that dominates here, up to the ponds south of Nîmes.
The Costières
The Costières are the first relief encountered in the Gard after the Camargue. Its hills, between 80 and 100 m in altitude, with a high point at the Puech de Dardaillon forest (146 m) in Générac, dominate Nîmes to the south. A small territory of 40 km between the communes of Beaucaire and Vauvert, its panorama offers a horizon on the Cevennes and the Alpilles. It is well known for its wine of controlled appellation costières-de-nîmes, registered only since 1986, but reputed since the Middle Ages, strongly marked by the stony ground on which its grapes grow. The same type of hills can be found in and around Quissac and Lédignan, where a large part of the land is also dedicated to wine production.
The Garrigues
Between the north-east of the Gard, between the towns of Bagnols-sur-Cèze in the extreme east, Vézénobres in the west and Nîmes in the south, there is a succession of faulted plateaus and hills, made of more or less hard limestone, often shallow, poor in humus. There develops a vegetation typical of dry environments, rich and particularly resistant to high temperatures, which is called "garrigue". The Garrigues can have massive forms, with relatively gentle slopes, interspersed with steep slopes, or asymmetrical, steep forms. They alternate with the plains and the cultivated alluvial basins in the surroundings.
Causses and Cevennes
Mount Aigoual, 1 567 m, is the highest point of the Gard part of this very old chain of hills and mountains, with a long and narrow ridge. From Le Vigan to Génolhac, passing through Sumène, Saint-André-de-Valborgne, Saint-Jean-du-Gard and La Grand-Combe, the roads are built on schist and granite. Anduze and Alès are considered the gateway to the Cevennes. The causses, imposing limestone masses of the neighboring plateaus, hollowed out and fragmented under the effect of alkaline sediments, rest on the crystalline massif. At the western end of the Gard, the Causse de Blandas offers a striking view of the cirque of Navacelles.
Hydrography
Small rivers such as the Hérault and the Virdoule, which flow from the Cévennes through the Garrigues into the Mediterranean, are fed by a large number of very irregularly-flowing streams. These in turn are fed by small streams that are subjected to heavy rainfall. These mineralized waters also flow through networks of natural underground galleries and caves. Several rivers known as gardons flow through the Cévennes valleys, and are distinguished by the villages they pass through: gardon de Saint-André, gardon de Saint-Jean, gardon du Mialet, etc. The small gardons form the large gardons. The smaller Gardons form the larger Gardons, the Anduze and Alès, which eventually join to form the Gard. The latter flows under the Pont du Gard bridge to join the Rhône at Vallabrègues. The Cèze rises in Lozère at Saint-André-Capcèze, on the border of the département, swells with mountain streams and ends its course in the Rhône.
