Weather

Weather

Although pantano means ‘swamp’ in both Spanish and Portuguese, the Pantanal is not a swamp but, rather, a vast alluvial plain. In geological terms, it is a sedimentary basin of quaternary origin, the drying remains of an ancient inland sea called the Xaraés, which began to dry out, along with the Amazon Sea, 65 million years ago.

First sea, then immense lake and now a periodically flooded plain, the Pantanal – 2000km upstream from the Atlantic Ocean yet just 100m to 200m above sea level – is bounded by higher lands: the mountains of the Serra de Maracaju to the east, the Serra da Bodoquena to the south, the Paraguayan and Bolivian Chaco to the west and the Serra dos Parecis and Serra do São Geronimo to the north. From these highlands the rains flow into the Pantanal, forming the Rio Paraguai and its tributaries (which flow south and then east, draining into the Atlantic Ocean).

During the wet season (November to March), the rivers flood their banks, inundating much of the low-lying Pantanal and creating cordilheiras (vegetation islands above the high-water level), where the animals cluster together. The waters reach their high mark – up to 3m – in January or February, then start to recede in March. This seasonal flooding has made systematic farming impossible and has severely limited human incursions into the area. However, it does provide an enormously rich feeding ground for wildlife.

The floodwaters replenish the soil’s nutrients, which would otherwise be very poor, due to the excessive drainage. The waters teem with fish, and the ponds provide excellent niches for many animals and plants. Enormous flocks of wading birds gather in rookeries several square kilometers in area.

Later in the dry season, the water recedes, the lagoons and marshes dry out and fresh grasses emerge on the savanna (the Pantanal’s vegetation includes savanna, forest and meadows, which blend together, often with no clear divisions). The hawks and jacarés compete for fish in the remaining ponds. As the ponds shrink and dry up, the jacarés crawl around for water, sweating it out until the rains return.

When to go

Go whenever you can, but if possible go during the dry season (April/May to September/October). The best time to watch birds is from July to September, when they are at their rookeries in great numbers, the waters have receded and the bright-green grasses pop up from the muck. Temperatures are hot by day and cool by night, with occasional short bursts of rain.

Flooding, incessant rains and heat make travel difficult during the wet season (November to March), though this time is not without its special rewards – this is when the cattle and wildlife of the Pantanal clump together on the cordilheiras. However, the islands are covered with dense vegetation that can make spotting wildlife difficult. In September and October, the driest two months, the chances for spotting jaguar rise dramatically – the Pantanal is the last great stronghold for the biggest and most elusive of the American cats. The heat peaks in November and December, when temperatures higher than 40°C (104°F) are common, roads turn to breakfast cereal, and the mosquitoes are out in force. Many hotels close at this time.

The heaviest rains fall in February and March. Roads become impassable and travel is a logistical nightmare. Every decade or so, the flooding is disastrous, killing both humans and animals.

Fishing is best during the first part of the dry season (April to May), when the flooded rivers settle back into their channels, but locals have been known to lasso 80kg fish throughout the dry season. This is some of the best fishing in the world. There are about 20 species of piranha, as well as the tasty dourado, a feisty fellow (known locally as the river tiger) that reaches upwards of 9kg and preys on hapless fellow fish. Other excellent catches include pacu, suribim, bagre, giripoca, piraputanga, piapara, cachara, pirancajuva and pintado, to name but a few.

Although hunting is not allowed, fishing – with the required permits – is encouraged between February and October. It is, however, prohibited during the piracema (breeding season) from November to the end of February, though the time frame varies year to year. Banco do Brasil branches in Cuiabá, Campo Grande and Coxim issue permits (from shore/boat R$24/60) valid for three months for fishing in the Pantanal. National fishing permits valid for one year are also available from IBAMA offices (Cuiabá 0xx65-644 1200, Campo Grande 0xx67-3317 2952, Corumbá 0xx67-3231 6096, Coxim 0xx67-3291 2310).