Climate Insights for Rosario

The climate in Rosario is warm and mild. The average annual temperature is 18°C and approximately 854mm of precipitation falls per year. April is the wettest month, receiving around 113mm of rainfall. Rosario is in the Southern Hemisphere. The seasons are reversed — summer runs from December to February, while winter falls between June and August. The summer months are: January, December, February. The coldest months are July, June, August, when temperatures can drop to 6°C.

Temperatures in Rosario vary considerably across the year, with a 25°C difference between the coldest and warmest months. The warmest month is January, when average highs reach 31°C and the mean temperature sits around 25°C. July is the coolest month, with minimum temperatures around 6°C and an average of 11°C. On average, daily temperatures fluctuate by about 11°C between overnight lows and afternoon highs. The sharpest temperature change occurs between April and May, with a 4°C shift in average temperatures.

Rosario is a moderately rainy area, receiving approximately 854mm of precipitation annually, which averages out to around 71mm per month. The wettest month is April, averaging 113mm of rainfall. January and March also tend to see above-average precipitation. The driest month is June, with just 24mm. That's 89mm less than April, the wettest month. Precipitation varies noticeably between seasons, with the first half (January to June) of the year generally seeing more rainfall.

Rosario is mildly breezy, with an average annual wind speed of 17km/h. For context, sustained winds below 12km/h are generally light, while anything above 25km/h is considered strong. The windiest month is October, averaging 19km/h, though still comfortable for most outdoor activities. The calmest conditions occur in February, with average winds dropping to 15km/h, making it an ideal period for wind-sensitive activities. Wind conditions are fairly consistent throughout the year, varying by only 4km/h between the calmest and windiest months.

It is currently autumn in Rosario, which began on March 20, 2026. Rosario is in the Southern Hemisphere, where the seasons are reversed — spring starts in September, summer in December, autumn in March, and winter in June. The warmest period peaks in January at around 31°C, while the coldest stretch bottoms out in July near 6°C. Winter is next, beginning on June 21, 2026 — 90 days from now.

The best time to visit Rosario is during February, September, October, November and December, when the weather is most comfortable for travellers. During these months, average temperatures hover around 21°C with modest rainfall averaging 72mm per month. By contrast, January can be uncomfortably hot with highs reaching 31°C, while July is the coldest period with lows dropping to 6°C. Despite being the best months overall, some rain is still likely — pack a waterproof layer and plan a mix of indoor and outdoor activities.

The table below shows monthly climate averages for Rosario based on historical weather data. Min and max temperatures represent typical overnight lows and afternoon highs for each month, shown in degrees Celsius (°C). Precipitation is measured in millimetres (mm) and indicates the average total rainfall per month. Wind speed is the average sustained speed in kilometres per hour (km/h). All values are based on averages from over 10 years of historical weather data. The current month is highlighted for quick reference.