Climate Insights for Iaçu

The climate in Iaçu is hot. The average annual temperature is 25°C and approximately 510mm of precipitation falls per year. January is the wettest month, receiving around 265mm of rainfall. Iaçu 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: March, December, April. The coldest months are July, August, September, when temperatures can drop to 18°C.

Iaçu sees moderate temperature variation throughout the year, ranging from 18°C to 33°C. The warmest month is March, when average highs reach 33°C and the mean temperature sits around 28°C. July is the coolest month, with minimum temperatures around 18°C and an average of 23°C. On average, daily temperatures fluctuate by about 10°C between overnight lows and afternoon highs.

Iaçu is a relatively dry area, receiving approximately 510mm of precipitation annually, which averages out to around 42mm per month. The wettest month is January, averaging 265mm of rainfall. September and October also tend to see above-average precipitation. The driest month is December, with just 14mm. That's 251mm less than January, 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.

Iaçu is relatively calm, with an average annual wind speed of 3km/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 3km/h, though still comfortable for most outdoor activities. The calmest conditions occur in January, with average winds dropping to 2km/h, making it an ideal period for wind-sensitive activities. There is moderate seasonal variation in wind speed, with a 1km/h gap between the calmest and windiest months.

It is currently winter in Iaçu, which began on June 21, 2026. Iaçu 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 March at around 33°C, while the coldest stretch bottoms out in July near 18°C. Spring is next, beginning on September 23, 2026 — 61 days from now.

The best time to visit Iaçu is during June, July, August and September, when the weather is most comfortable for travellers. During these months, average temperatures hover around 23°C with modest rainfall averaging 27mm per month. By contrast, March can be uncomfortably hot with temperatures reaching 33°C. With minimal rainfall expected, you can pack light and plan outdoor activities with confidence.

The table below shows monthly climate averages for Iaçu 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.