Climate Insights for Viamão

The climate in Viamão is warm and mild. The average annual temperature is 20°C and approximately 1386mm of precipitation falls per year. Viamão receives a notable amount of rainfall throughout the year, including during its driest month. Viamão 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 11°C.

Viamão sees moderate temperature variation throughout the year, ranging from 11°C to 30°C. The warmest month is January, when average highs reach 30°C and the mean temperature sits around 26°C. July is the coolest month, with minimum temperatures around 11°C and an average of 15°C. Daily temperature variation is modest, with an average difference of 8°C between highs and lows. The sharpest temperature change occurs between April and May, with a 4°C shift in average temperatures.

Viamão is a fairly wet location, receiving approximately 1386mm of precipitation annually, which averages out to around 115mm per month. The wettest month is September, averaging 167mm of rainfall. May and October also tend to see above-average precipitation. The driest month is April, with just 82mm. That's 85mm 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.

Viamão is mildly breezy, with an average annual wind speed of 20km/h. For context, sustained winds below 12km/h are generally light, while anything above 25km/h is considered strong. The windiest month is December, averaging 22km/h, noticeable enough to affect lighter outdoor activities. The calmest conditions occur in June, with average winds dropping to 17km/h, making it an ideal period for wind-sensitive activities. Wind conditions are fairly consistent throughout the year, varying by only 5km/h between the calmest and windiest months. Wind tends to pick up during the summer months. The seasonal averages are 18km/h in winter, 22km/h in spring, 21km/h in summer, 19km/h in autumn.

It is currently autumn in Viamão, which began on March 20, 2026. Viamão 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 30°C, while the coldest stretch bottoms out in July near 11°C. Winter is next, beginning on June 21, 2026 — 89 days from now.

The best time to visit Viamão is during April and August, when the weather is most comfortable for travellers. During these months, average temperatures hover around 19°C with modest rainfall averaging 86mm per month. By contrast, January can be uncomfortably hot with highs reaching 30°C, while July is the coldest period with lows dropping to 11°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 Viamão 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.