The climate of the Pantanal is tropical, with hot and rainy summers, and dry and sunny winters, characterized by warm days and cool nights. Being in the Southern Hemisphere, the seasons are reversed compared with Europe or North America.
Here are the average temperatures of the city of Corumbà, located in the south-central part of the region.
Average temperatures - Corumbá

Corumbá	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
Corumbá	J	F	M	A	M	J	J	A	S	O	N	D
Min (°C)	23	23	23	21	20	17	18	18	20	22	23	23
Max (°C)	33	32	32	31	28	27	27	29	31	33	33	33
Min (°F)	73	73	73	70	68	63	64	64	68	72	73	73
Max (°F)	91	90	90	88	82	81	81	84	88	91	91	91

The rains are concentrated in the warm period, from October to April, with a peak between November and March. The rainfall amount varies between 1,000 and 1,300 millimetres (40 and 51 inches) per year, therefore it is not so abundant, yet the Pantanal is the largest wetland in the world, since there are major rivers such as the Paraguay and its tributaries, which overflow in the rainy season.
Here is the average precipitation.
Average precipitation - Corumbá

Corumbá	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec	Year
Corumbá	J	F	M	A	M	J	J	A	S	O	N	D	Y
Prec. (mm)	180	140	140	80	55	40	30	25	45	90	115	155	1100
Prec. (in)	7.1	5.5	5.5	3.1	2.2	1.6	1.2	1	1.8	3.5	4.5	6.1	43.3
Days	18	15	14	10	6	4	5	5	7	12	15	17	128

Most of the Pantanal is located in Brazil, in the states of Mato Grosso and Mato Grosso do Sul, but there is also a part in eastern Bolivia, along the border with Brazil, and a small portion in northern Paraguay. Since it hosts an extraordinary variety of plant and animal species (such as jaguars, capybaras, tapirs and hyacinth macaws), the Pantanal was declared a World Heritage Site by UNESCO in 2000.



Winter, from mid-May to mid-August, is dry, with rare showers. During the day it's hot, especially in the north (see Caceres), where the temperature normally fluctuates around 31/32 °C (88/90 °F), while it remains lower, around 27/28 °C (81/82 °F), in the southern part (see Corumbà). Sometimes, however, it can be very hot even in winter, with peaks of 35 °C (95 °F) in the south and 37 °C (99 °F) in the north.
Nights are usually cool, with minimum temperatures around 15 °C (59 °F) in the southernmost part, and possible mists or fogs at night, but sometimes they can be cold, when the wind blows from Argentina, so that minimum temperatures can reach as low as 0 °C (32 °F) in the southern part, and 5/7 °C (41/45 °F) in the north.

In spring, from mid-August to mid-November, the temperature begins to rise, so that it gradually becomes the hottest season of the year, especially in the north: in Caceres the maximum temperature hovers around 34 °C (93 °F) between August and November, with peaks of 40 °C (104 °F); in the south the temperature is lower by a couple of degrees Celsius (around 3.5 °F), but the peaks are equally around 40 °C (104 °F). In September, the first rains begin to show up, generated by the growing heat, but only in October they reach a certain importance, so that they total about 100 mm (4 in) per month in the centre-south, and 130 mm (5.1 in) in the north.

Summer, from mid-November to late March, is hot, humid and rainy. Rainfall occurs mostly in the form of intense downpour or thunderstorm. In this period the floods make it difficult to get around. We have seen how the hottest time of the year is the spring, at the end of the dry season, but in fact sometimes the temperature can approach 40 °C (104 °F) also in summer, during hot and sunny periods, which can occur in this season as well.

In autumn, from April to mid-May, there's a gradual decrease in both temperature and rain. Also, rivers return to their banks.



The amount of sunshine in Pantanal is not great, nor poor, because the sun can shine in all seasons.
Sunshine - Corumbá

Corumbá	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
Corumbá	J	F	M	A	M	J	J	A	S	O	N	D
Sun (hours)	7	7	7	7	7	6	8	6	6	7	8	7

The best time to visit the Pantanal is the austral winter, from mid-May to mid-August, being the coolest and driest of the year. You should be equipped for the possible cold at night, and dress in layers, because during the day it can be hot. Autumn, from April to mid-May, is a good period too: it is hotter, especially in April, there may be some more showers, but it is also less likely that it gets cold at night.