Climate Insights for Arroio Grande

The climate in Arroio Grande is warm and mild. The average annual temperature is 18°C and approximately 1355mm of precipitation falls per year. Arroio Grande receives a notable amount of rainfall throughout the year, including during its driest month. Arroio Grande 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, February, December. The coldest months are July, June, August, when temperatures can drop to 9°C.

Arroio Grande sees moderate temperature variation throughout the year, ranging from 9°C to 29°C. The warmest month is January, when average highs reach 29°C and the mean temperature sits around 24°C. July is the coolest month, with minimum temperatures around 9°C and an average of 12°C. On average, daily temperatures fluctuate by about 9°C between overnight lows and afternoon highs. The sharpest temperature change occurs between April and May, with a 4°C shift in average temperatures.

Arroio Grande is a fairly wet location, receiving approximately 1355mm of precipitation annually, which averages out to around 113mm per month. The wettest month is September, averaging 165mm of rainfall. January and August also tend to see above-average precipitation. The driest month is February, with just 84mm. That's 81mm less than September, the wettest month. Rainfall is relatively evenly distributed throughout the year, so there is no pronounced dry or wet season to plan around.

Arroio Grande is mildly breezy, with an average annual wind speed of 19km/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 21km/h, noticeable enough to affect lighter outdoor activities. The calmest conditions occur in May, with average winds dropping to 18km/h, making it an ideal period for wind-sensitive activities. Wind conditions are fairly consistent throughout the year, varying by only 3km/h between the calmest and windiest months.

It is currently autumn in Arroio Grande, which began on March 20, 2026. Arroio Grande 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 29°C, while the coldest stretch bottoms out in July near 9°C. Winter is next, beginning on June 21, 2026 — 89 days from now.

The best time to visit Arroio Grande is during February and November, when the weather is most comfortable for travellers. During these months, average temperatures hover around 22°C with modest rainfall averaging 88mm per month. By contrast, January can be uncomfortably hot with highs reaching 29°C, while July is the coldest period with lows dropping to 9°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 Arroio Grande 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.