When to Go
In Brasília and much of the West you can count on clear days and comfortable temperatures from March to July (the mean temperature is 22°C/75°F). The rainy season runs from November to February; in August and September the mercury often rises to 38°C (100°F). When congress adjourns (July, January, and February), the city's pulse slows noticeably, and hotel rooms are easier to come by. It's nearly impossible to get a room during major political events. On the other hand, popular holidays such as New Year's and Carnival are much less hectic than in other cities.
The best season to visit the Pantanal depends on what you intend to do. If the plan is to take photos of wildlife, the ideal time is the dry season running from June to October. As the waters dwindle, animals are concentrated in a smaller area, making them easier to spot. For fishing, the best time to visit is from August to October, before the onset of the rainy season, when most fish move upstream to spawn.