Climate Insights for Rosario

The climate in Rosario is warm and mild. The average annual temperature is 24°C and approximately 522mm of precipitation falls per year. August is the wettest month, receiving around 155mm of rainfall. Rosario is in the Northern Hemisphere. Summer begins at the end of June and lasts through September. The summer months are: June, May, July. The coldest months are January, December, February, when temperatures can drop to 9°C.

Temperatures in Rosario vary considerably across the year, with a 30°C difference between the coldest and warmest months. June is the hottest month, with daytime highs reaching 39°C and an average of 31°C. January is the coolest month, with minimum temperatures around 9°C and an average of 17°C. On average, daily temperatures fluctuate by about 15°C between overnight lows and afternoon highs. The sharpest temperature change occurs between October and November, with a 5°C shift in average temperatures.

Rosario is a relatively dry area, receiving approximately 522mm of precipitation annually, which averages out to around 43mm per month. The wettest month is August, averaging 155mm of rainfall. July and September also tend to see above-average precipitation. The driest month is May, with just 1mm. That's 154mm less than August, the wettest month. Rainfall is heavily concentrated in certain months, creating a distinct wet and dry season. Visitors should plan around these patterns, as the difference between peak and low months is dramatic.

Rosario is relatively calm, with an average annual wind speed of 11km/h. For context, sustained winds below 12km/h are generally light, while anything above 25km/h is considered strong. The windiest month is May, averaging 15km/h, though still comfortable for most outdoor activities. The calmest conditions occur in August, with average winds dropping to 9km/h, making it an ideal period for wind-sensitive activities. There is moderate seasonal variation in wind speed, with a 6km/h gap between the calmest and windiest months.

It is currently spring in Rosario, which began on March 20, 2026. Rosario is in the Northern Hemisphere, where spring begins in March, summer in June, autumn in September, and winter in December. The warmest period peaks in June at around 39°C, while the coldest stretch bottoms out in January near 9°C. Summer is next, beginning on June 21, 2026 — 83 days from now.

The best time to visit Rosario is during January, February, March, April, November and December, when the weather is most comfortable for travellers. During these months, average temperatures hover around 20°C with modest rainfall averaging 15mm per month. By contrast, June can be uncomfortably hot with temperatures reaching 39°C. With minimal rainfall expected, you can pack light and plan outdoor activities with confidence.

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.