, 2018 The department borders
Nord (to the north),
Somme and
Oise (to the west),
Ardennes and
Marne (east), and
Seine-et-Marne (south-west) and
Belgium (Province of
Hainaut) (to the north-east). The river
Aisne crosses the area from east to west, where it joins the
Oise. The
Marne forms part of the southern boundary of the department with the department of Seine-et-Marne. The southern part of the department is the geographical region known as
la Brie poilleuse, a drier plateau known for its dairy products and
Brie cheese. According to the 2003 census, the forested area of the department was 123,392 hectares, or 16.6%, for an average metropolitan area of 27.4%. The landscape is dominated by masses of rock which often have steep flanks. These rocks appear all over the region, but the most impressive examples are at
Laon and the
Chemin des Dames ridge.
Principal towns The department of Aisne includes one medium-sized city (Saint-Quentin) and three small cities (Laon, Soissons, and Château-Thierry), to which may be added the conglomeration formed by Chauny and Tergnier. There are many other agglomerations of an urban character because Aisne has been densely populated since before the 19th century. The villages are numerous and rather small. The most populous commune is
Saint-Quentin; the prefecture
Laon is the third-most populous. As of 2023, there are 7 communes with more than 10,000 inhabitants: See also: List of the
communes of the Aisne department.
Hydrography river at
Soissons, 2008 The
Scheldt (which takes its source near
Le Catelet), the
Aisne, the
Marne, the
Ourcq, the
Vesle, the
Somme (which rises in
Fonsommes), the
Oise, and the
Serre. In the south of the department, there is the
Surmelin, the Verdonnelle, and the
Dhuys (this river is channeled into the Dhuis Aqueduct, 131 km long, to supply drinking water to Paris since 1 October 1865 and also more recently the Leisure Park of
Marne-la-Vallée). The department is also crossed by numerous canals (e.g. the
Canal of Saint-Quentin, 93 km).
Climate There is an average of 500 to 750 mm precipitation annually.
Weather Data for Saint Quentin – Roupy ==Transport==