The overall climate ranges from subtropical to temperate, and like most lands in the region, Paraguay has only a wet and dry period. Winds play a major role in influencing Paraguay's weather: between October and March, warm winds blow from the Amazon Basin in the North, while the period between May and August brings cold winds from the Andes.
The lack of mountain ranges to provide a natural wind barrier allows winds to develop speeds as high as 100 miles per hour (161 km/h). This also leads to significant changes in temperature within a short span of time; between April and September, temperatures will sometimes drop below freezing. January is the hottest summer month, with an average daily temperature of 84 degrees.
Rainfall varies dramatically across the country, with substantial rainfall in the eastern portions, and semi-arid conditions in the far west. The far eastern forest belt receives an average of 67 inches (170 cm) of rain annually, while the western Chaco region typically averages no more than 20 inches (50 cm) a year. Furthermore, the rains in the west tend to be irregular and evaporate more quickly, contributing to the aridity of the area
