Paraguay is generally warm most of the year. The Tropic of Capricorn runs through the city of Belén in northern Paraguay, dividing the country into a tropical zone in the north and a temperate zone in the south. The hottest time of the year is from November to February, when daytime temperatures can reach around 45°C and high atmospheric pressure makes walking on the road difficult. Winter (June to September) is pleasantly warm (around 20-25°C) during the day, usually sunny and dry, but often cold at night with occasional morning frosts. January is the warmest month with an average maximum temperature of 36°C, and July is the coldest month with an average minimum temperature of 9°C.
Eastern Paraguay can be very wet, while western Paraguay (the Chaco) is dry. There is no real rainy season, but from September to November electrical storms become more frequent and off-road travel can be more difficult. The climate generally follows the prevailing winds, with the viento sur (south wind) bringing cooler temperatures from Patagonia and the viento norte (north wind) bringing warmer temperatures from the tropics.