With a land area of 176,215 km² (of which 175,016 km² is the total sum of the departments and 1,199 km² comprises the sum of the artificial lakes of the Negro River), Uruguay also exercises its sovereignty over several islands located in the Uruguay River (with a total of 105 km²), 16,799 km² of jurisdictional waters (Río Uruguay, Río de la Plata and Laguna Merín) and a territorial sea area of 125,057 km². In turn, Uruguay maintains two border disputes with Brazil over the territories known as Isla Brasilera and Rincón de Artigas, which occupy an area of 237 km². The total area of the Uruguayan territory covers 318,413 km².
The relief is linked in the southern part to the Pampean lands and is made up of vast undulating plains furrowed by low-elevation hills called blades. The most important are those that belong to the Haedo Blade and the Big Blade. Its highest point is Cerro Catedral, with 514 meters above sea level.
The most important hydrographic basin is that of the Uruguay River, which is used as a means of communication with other neighboring countries. The Río de la Plata basin is made up of short-course rivers. The Laguna Merín basin is made up of the Yaguarón, Tacuarí, Cebollatí and other rivers.
Two large structural areas are distinguished: the peneplains and the plains.
They are remains of ancient mountain ranges, today totally eroded. You have a fundamentally crystalline character. These are gently undulating reliefs with rivers very embedded in the landscape. They are spread over most of the country and three subsectors are distinguished:
- sedimentary in the northeast,
- basaltic on the coast
- crystalline in the center-south and on the crystalline island of Rivera.
They are the product of the accumulation of sediments contributed by rivers, especially Uruguay. They are remarkably flat plains, but more undulating inland than on the coast. They are arranged peripherally and are also subdivided into three sectors:
- littoral plain of the Uruguay River,
- the Platense
- the Atlantic, extended around the Merín lagoon.
The small undulations of the terrain are due either to the irregularities of the accumulation of clays or to the outcrop of granite hills. These hills are called blades, and they are characterized by having a rounded top and gentle slopes. The most important ones are black knife, Grande knife, Haedo and Santa Ana.
Its highest point is Cerro Catedral, with 514 meters above sea level. Other outstanding elevations for the country are the Cerro de las Ánimas, with 501 meters, the Cerro de Montevideo, the Arequita and the Pan de Azúcar (in Maldonado). The blade system also serves as a watershed.
They are the undulations that we find between two rivers or streams.
In Uruguay there are two large sets of blades that divide Uruguay in two: north of the Río Negro: Cuchilla de Haedo and Cuchilla de Santa Ana and south of the Río Negro: Cuchilla Grande. (Cerro Catedral): This blade in its portion Northeast is sandwiched between the Negro River and the tributaries of Laguna Merín. It begins relatively high in the region of the Sierra Aceguá (400 mts.) Then falls towards the sources of the Tacuarí river and rises again where the Cuchilla del Olimar and the Sierra de Sosa emerge.
In the direction of Laguna Merín, the Cuchillas de los Ríos, Cerro Largo, Dionisio and Palomeque emerge in Treinta y Tres. Towards the west the Cuchilla Grande del Durazno emerges and to the south that of Mansavillagra. It forks extending towards the Uruguay River ending in Punta Gorda de Colonia.
The main divide called Cuchilla de Haedo separates the waters that go to the Negro River and those that run to the Uruguay River; It begins with the name Cuchilla Negra (a typical tabular blade of considerable height) from which erosion has separated numerous isolated hills or arranged in rows and ends at the confluence of the Uruguay and Negro rivers, called Rincón de las Gallinas. The corners of the land bounded by rivers are called corners. For example, the Rincón del Yí, between the Río Negro and the Yí.
The totally border Santa Ana blade is an extension of the Haedo blade. In the Haedo blade, the Lunarejo and de la Virgen hills and the Tambores hill (275 mts.) Stand out. The eastern edge of the Black Blade and the Haedo is steep in the shape of an escarpment and the western edge is smooth. The ramifications of the Cuchilla de Haedo to the west separate the tributaries of the Uruguay River. The most important are those of Belén, Arapey, Dayman, Queguay and del Rabón.
They are those elevations that stand out in the landscape (Cerro Chato, Cerro de las Ánimas)
The group of hills aligned and united at their bases is called a sierra. The particular characteristic of each mountain range depends on the type of rock that constitutes it because they react differently to erosive agents. For example, in the Sierra Tambores formed by basaltic heights, the hills with a flattened top dominate, while in the northern portion of the Sierra de las Animas granite predominates, constituting typically rounded hills. In the southern portion, the Sierra de las Animas has different characteristics because the predominant rock is trachyte. In the Sierra de la Ballena, the quartzites determine a crested appearance.
Uruguay is the only South American country that is entirely in the temperate zone. The absence of important hydrographic systems contributes to the fact that the spatial variations of temperature, rainfall and other parameters are not so high. The average annual temperature for the country is around 17 ° C.
The month of March presents the highest rains in most of the territory with a maximum of 140 mm, covering part of the departments of Artigas, Rivera, Salto and Tacuarembó and a minimum isohyeta of 90 mm. which is located to the southeast. The month with the lowest average rainfall is December for the entire country, between 100 mm. on Artigas and 60 mm. about Rocha.
Uruguay has a dense and highly branched hydrographic network. All river currents have a single slope, the Atlantic Ocean.
According to bridgat, the climate in Uruguay is temperate and humid (average 17 ° C), with hot summer and more or less homogeneous rainfall throughout the year. In Uruguay, where maritime as well as continental influence are noted, the distribution of rainfall presents a double rainy season, with a main maximum in autumn and a secondary maximum in spring. Due to their latitude, between 30ºC and 35ºC, the four seasons are clearly differentiated by temperature.