The climate of much of Paraguay is sub-tropical, with the rainy season during the austral summer from October to April. Average annual rainfall is about 1,000 mm in Asunción area, about 1500 mm in the forest eastern regions, and 800 mm in the Chaco. The great distance from the sea influence the rains, which increase in the east, and decreased significantly in western areas. The area of Chaco has a tropical climate with hot summers and warm winters. The summer lasts from December to March and besides being the rainy season also has high temperatures with average maximum temperatures between December and February, of 30°C-33°C in the capital Asuncion, while in the region of Gran Chaco and other areas of the north may reach 38°C. Winters are temperate and dry with average temperatures between 13°C and 21°C.

Because of the great summer heat and rain, the best period for the visit of Paraguay are the winter months between May and September.