Paraguay has a subtropical to tropical climate with hot summers, mild winters, and no real cold season. Temperatures in the capital, Asunción, range from average highs of 92°F (33°C) in January to 74°F (23°C) in July. The country splits into two distinct climate zones divided by the Paraguay River, and understanding that split is key to knowing what weather to expect.
Two Regions, Two Climates
Paraguay is divided into the Eastern region (Paraneña) and the Western region (Chaco), and they feel like different countries weather-wise.
The Paraneña region, where most of the population lives, has a subtropical, humid climate with a mean annual temperature of 24°C (75°F). Rainfall is abundant and spread fairly evenly across the year, with over 1,700 mm falling annually near the Paraná River. Seasonal temperature swings are moderate. This is green, lush countryside with rolling hills and river systems.
The Chaco region is hotter and much drier. Mean annual temperature sits around 28°C (82°F), and rainfall drops dramatically to as little as 400 mm per year in the driest areas. Unlike the east, the Chaco has distinct wet and dry seasons, bordering on semi-arid. It’s sparsely populated scrubland and thorny forest, with punishing heat in summer and long dry stretches that can last months.
Summer Heat and Humidity
Paraguayan summers run from December through February, and they are intense. Daytime temperatures of 38°C (100°F) are fairly common, and moist tropical air keeps conditions warm and sticky from October through March. The humidity is what makes it difficult. Skies will stay almost cloudless for a week to ten days while temperature and humidity climb steadily. As the soggy heat nears intolerable limits, thunderstorms blow in from the south along a cold front, and temperatures can plunge as much as 15°C in a matter of minutes. This cycle of building heat followed by dramatic storms repeats throughout the summer months.
Rainfall during these months runs between 130 and 150 mm per month in Asunción, with November typically the wettest month at around 151 mm.
Mild, Dry Winters
Winter in Paraguay (June through August) is the coolest and driest period but far from truly cold. July is the coldest month, with average lows around 56°F (14°C) and highs near 74°F (23°C) in Asunción. The Paraná Plateau in the east runs slightly cooler, with mean July temperatures around 17°C. Rainfall drops to about 50 mm per month in July and August, making these the driest months of the year.
Frost is rare in most of the country, though occasional cold waves from Patagonia can push overnight temperatures lower than expected. These cold snaps are brief, typically lasting a few days before warm conditions return.
Rainfall Patterns Month by Month
Paraguay doesn’t have a true monsoon season, but rainfall is noticeably uneven across the year. Here’s a general picture of monthly rainfall in the eastern part of the country:
- Wettest months (October to March): 130 to 151 mm per month, with November peaking highest
- Driest months (June to August): 50 to 71 mm per month
- Transitional months (April, May, September): 77 to 145 mm per month
In the eastern Paraneña region, rain is distributed relatively evenly, so there’s no prolonged dry spell that shuts down travel or daily life. The Chaco is a different story. Its wet season concentrates rainfall into a few months, leaving long arid stretches where water becomes scarce and dust dominates the landscape.
El Niño and Flooding
Paraguay is vulnerable to the El Niño climate cycle, which can dramatically increase rainfall during the Southern Hemisphere summer (December through February). During El Niño years, southern Paraguay receives far more rain than the long-term average. The Paraná, Uruguay, and Paraguay rivers can overflow, displacing thousands of people in riverside communities. Flooding along the Paraguay River in Asunción has forced mass evacuations in multiple El Niño events. La Niña years tend to bring the opposite: reduced rainfall and drought conditions, particularly damaging in the already dry Chaco.
Best Months to Visit
September through early December offers the most comfortable window. Temperatures are warm but not extreme, ranging from highs of 27°C in September to 33°C by December. Rainfall picks up gradually but hasn’t reached its summer peak. April and May are also pleasant, with cooler temperatures (highs around 25 to 28°C) and moderate rain.
December through February is the hottest and most humid stretch. If you’re visiting Iguazú Falls on the eastern border, those months bring the most impressive water volume, though heavy rain can close surrounding rainforest trails. July and August are the driest and coolest, comfortable during the day but occasionally chilly at night. Paraguay has no real peak tourist season, so crowds are rarely an issue regardless of timing.