Climate: The Pantanal Savannah

The Pantanal has two well-defined seasons: a rainy and a dry season. Both seasons are good for travel to this region and the activities are tailored to the weather and the flooding cycle. The rainy season occurs from October to March with February and March being the wettest months. The months July and August see the least rainfall.
The rainy season corresponds roughly to the seasonal floods. From December through April the many rivers in the Pantanal overflow their banks and much of the savanna is covered with a shallow sheet of water. The highest water months are generally January and February. These great environmental fluctuations are one of the reasons that the wildlife is so concentrated.

Seasons and Weather in the Pantanal

The Rainy Season, October - March
While the rain can be heavy at times in the rainy season, it rarely lasts for more than a few hours. Most mornings the skies are clear but clouds gather as the day warms. In the mid- to late afternoon there is usually a rain shower, often accompanied by a rainbow. Though occasionally it may rain for two days at a time, rarely do showers last for more than a single afternoon. The nights are generally clear and the sky full of stars.
From October to March large areas of the Pantanal are covered by up to three meters of water forming lakes that are hundreds of square kilometers in extent. Many kinds of wildlife have adapted to this flood cycle. Fish, mollusks and aquatic plants range over the newly flooded land to feed and reproduce. Great numbers of fishing birds migrate into the region to feed and nest. Certain areas remain above the water and these serve as a refuge for land mammals which concentrate there. The average temperature is about 79º F (26.1º C).

The Dry Season, April to September
In April the weather turns dry and the water recedes from the broad flat savanna. Mammals follow the receding waters and congregate along river edges. Fish are concentrated into small water courses and fishing birds fly in to feast. Plants that once filled the flooded plains enter a state of hibernation, where they stay until the rains return. What was a huge flooded garden is transformed into a vast field of native grass. Small plants and flowers cover the ground. Shallow lakes form inland and they become feeding centers for animals that dine on the fish and other aquatic creatures that are isolated from the rivers. From July through the end of December the savanna is dry enough for vehicles to drive out into the bush. The average temperature is about 75º F (23.7º C).

The best time to go…
There are advantages to traveling during either season. While the rainy season can be quite rainy, the weather is a bit cooler. Also, the flooding of the savanna has the effect of concentrating animals on higher ground which can make them easier to see and photograph. The dry season also has its advantages. When the savanna has dried, many animals congregate at the edges of rivers where they can be easily seen by boat. The best time to travel to the Pantanal, therefore, is whenever it is convenient for you.