Pampas & Beaches
Pampas & Beaches Geography & Climate
Geography
The Pampas is one of the largest and most fertile plains on earth, and its defining characteristic is that there is almost nothing on it.
Flatness and soil
The plain extends for hundreds of kilometres with gradients so slight they are imperceptible, floored by deep wind-blown loess soils built up over the last two million years. These are among the most productive agricultural soils anywhere, deep, dark and free of stone, and they are the reason Argentina became a food exporter on a world scale.
The two ranges
Two low, ancient ranges interrupt it: Tandilia and Ventania, both of Precambrian and Palaeozoic rock, worn down to a few hundred metres over hundreds of millions of years. Cerro Tres Picos at 1,239 metres is the province’s highest point, and the quartzite at Sierra de la Ventana carries a natural rock window.
The coast
Around six hundred kilometres of Atlantic shore, almost all of it sand: long beaches backed by dune fields, some of which have been planted with pine to stabilise them, and a few cliff sections near Mar del Plata and Miramar where fossils erode out.
Water
Few rivers and very little relief, so the plain drains poorly and floods across large areas in wet years. Shallow saline lagoons dot the west.
Fossils in the cliffs
The low coastal cliffs between Mar del Plata and Miramar cut through Pleistocene deposits and erode continuously, exposing the bones of the giant mammals that lived on the plain until around ten thousand years ago — Glyptodon, the car-sized armoured relative of the armadillo, giant ground sloths and sabre-toothed cats. Charles Darwin collected here on the Beagle voyage, and the finds contributed directly to his thinking about extinction.
The delta
The Parana ends in a still-growing delta of sediment, advancing into the estuary by several dozen metres a year.
Climate Patterns
The Pampas has a temperate humid climate without extremes, which is exactly why it grows so much.
Summer
December to February averages 28 to 32°C with high humidity, and heatwaves push above 38. Thunderstorms are frequent and can be violent — the plain produces some of the most intense convective storms in the world, with hail large enough to destroy crops and occasional tornadoes, which is not widely known outside the region.
Winter
June to August is mild rather than cold, 8 to 15°C, with damp grey spells and occasional frost. Snow is very rare. The discomfort is the humidity and the wind rather than the temperature.
The pampero
A cold, dry wind that sweeps up from the south-west behind a front, often after a hot humid spell, dropping the temperature sharply within an hour and clearing the air. It is the plain’s characteristic weather event and gives the region its most reliable clear days.
Rain
Around 900 to 1,100 millimetres a year in the east, falling through all seasons, decreasing westward toward La Pampa. With so little relief, wet years produce extensive flooding that can leave farmland under water for months.
Why it grows so well
The combination is unusually favourable: deep soil, reliable rainfall spread through the year, a long growing season without extremes, and almost no frost damage in the east. Very few large plains anywhere have all four, which is the whole reason this region fed Europe in the nineteenth century and feeds a good deal of Asia now.
The coast
Cooler than inland in summer, with sea breezes, and the water is a bracing 18 to 21°C in January.