Weather in Buenos Aires in September 2025
Average weather
Average temperature in Buenos Aires in September
The temperature in September is +17°C on average, with a range between a maximum of +23°C during the day and a minimum of +6°C at night.
The average maximum temperature goes down 18% by the end of the month, compared with the beginning of the month, from +19°C to +16°C.
Is Buenos Aires warm or cold in September?
Buenos Aires is typically mild in September.
Maximum temperatures go up compared to the previous month from +16°C to +18°C. The minimum temperature also goes up from +9°C to +11°C.
Pack a light jacket as it will be warm in the day and cool in the evenings.
Take a look at how September is compared to other months in Buenos Aires:
Water temperature in Buenos Aires in September
Water in Buenos Aires in September is Cold. It varies from +12°C to +16°C, with an average of +14°C. This is almost similar to the air temperature, which averages +18°C.
In September, water temperatures are average relative to the rest of the year:
Can you swim in Buenos Aires in September?
Travel to Buenos Aires
Climate in Buenos Aires in September
| August | September | October | ||||
|---|---|---|---|---|---|---|
| Avg. temperature | ||||||
| +16°C | +18°C | +21°C | ||||
| Min. temperature | ||||||
| -1°C | 0°C | +2°C | ||||
| Max. temperature | ||||||
| +32°C | +31°C | +35°C | ||||
| Rainfall | ||||||
| 58 mm | 69 mm | 102 mm | ||||
| Wind | ||||||
| 3 m/s | 4 m/s | 4 m/s | ||||
| Avg. water temperature | ||||||
| +12°C | +14°C | +17°C | ||||
| Humidity | ||||||
| 74% | 72% | 71% | ||||
| Air pressure | ||||||
| 1018 HPa | 1017 HPa | 1015 HPa | ||||
| Sunny days | ||||||
| 12 | 11 | 10 | ||||
| Cloudy days | ||||||
| 10 | 9 | 7 | ||||
| Rainy days | ||||||
| 7 | 8 | 10 | ||||
| Snowy days | ||||||
| 0 | 0 | 0 | ||||
September weather is still as good as in August. It’s getting warmer as September arrives. The average maximum temperature goes up from +16°C to +18°C during the day. Prepare for more rain. Average rainfall goes from 58 mm to 69 mm. It feels drier, as humidity decreases from 74% to 72%. Winds are stronger in comparison to August, going up from 3 m/s to 4 m/s on average. The days becoming less sunny, going from 12 sunny days in August to 11 in September.
October brings much the same weather, it remains good.
Wind
The average wind speed is 4 m/s getting up to 8 m/s which is a medium breeze. You can feel it, especially getting out of the water.
The average wind speed in Buenos Aires is gradually decreasing during September, going from 3 m/s to 2 m/s over the course of the month.
Rain
How was the weather last September in Buenos Aires?
Climate Change over Years
The climate in Buenos Aires in September has not changed much over the last 43 years.
The average temperature was the lowest in 1983 (+20°C) and the highest in 2017 (+22°C). The driest year was 2008 with only 468 mm of rainfall, and the wettest year was 2014 with 1388 mm.
FAQ
Is September a good time to visit Buenos Aires?
Can you sunbathe in Buenos Aires in September?
Can you swim in Buenos Aires in September?
Is Buenos Aires rainy in September?
Is it sunny in Buenos Aires in September?
How much does it cost to fly to Buenos Aires in September?
Monthly weather in Buenos Aires
Source of the data
For this page, we’ve looked at the typical weather in Buenos Aires, based on historical hourly weather data from January 1, 1979, to December 31, 2023.
For past dates, we show actual recorded data at the location at that time. Forecasts are based on recorded weather during that day of the year, averaged over the total years for which we have records (unless stated otherwise). The daily temperature is the highest recorded temperature in the shadow during that day.