The climate is temperate, with precipitation of 600 to 1,200 mm (23.6 to 47.2 in) that is more or less evenly distributed throughout the year, making the soils appropriate for agriculture.

The coastal areas and most of the Buenos Aires Province are predominantly plain (with some wetlands) and the interior areas (mainly in the southern part of the Brazilian state of Rio Grande do Sul and Uruguay) have low ranges of hills (like Serras de Sudeste in Brazil and Cuchilla Grande in Uruguay).

The highest elevations of the Pampas region are found in the Sierra de la Ventana mountains, in the southern part of Buenos Aires Province, with 1,239 metres (4,065 ft) at the summit of Cerro Tres Picos.

However, most cities in the Pampas occasionally have high temperatures that push 38 °C (100 °F), as occurs when warm, dry, northerly winds blow from southern Brazil, northern Argentina or Paraguay.

The eastern areas have small peaks in the fall and the spring, with relatively rainy summers and winters that are only slightly drier.

Very intense thunderstorms are common in the spring and summer, and it has among the most frequent lightning and highest convective cloud tops in the world.

Mammals that are still fairly present include Brazilian guinea pig, southern mountain cavy, coypu, Pampas fox, Geoffroy's cat, lesser grison, white-eared opossum, Molina's hog-nosed skunk, big lutrine opossum, big hairy armadillo and southern long-nosed armadillo.

Notable former inhabitants of the Pampas include the giant elephant-sized ground sloth Megatherium americanum, alongside the smaller (though still large) ground sloths Mylodon, Glossotherium Lestodon and Catonyx, the rhinoceros like ungulate Toxodon, the camel-like Macrauchenia, the gomphothere (elephant-relative) Notiomastodon, the equines Equus neogeus and Hippidion, and the glyptodonts (car-sized relatives of armadillos) Glyptodon and Doedicurus, the bear Arctotherium and the sabertooth cat Smilodon populator.

Other causes that have been proposed are fires set by indigenous peoples for land clearance; the existence of heavy-bodied herbivores; and that the pampas are relicts of drier past climates.

"Overall, we expect that low propagule pressure, abiotic stresses, biotic resistance, and a paucity of specific symbionts might have exerted a synergistic influence in slowing tree invasion rates ".

The Uruguayan Savanna lies east of the Paraná River, and includes all of Uruguay, most of Entre Ríos and Corrientes provinces in Argentina, and the southern portion of Brazil's state of Rio Grande do Sul.

Central Argentina boasts a successful agricultural business, with crops grown on the Pampas south and west of Buenos Aires.

Starting in the 1840s but intensifying after the 1880s, European immigrants began to migrate to the Pampas, first as part of government-sponsored colonization schemes to settle the land and later as tenant farmers "working as either a sharecropper or as paid laborers for absentee landowners"[12] in an attempt to make a living for themselves.