Buenos Aires weather in September
Temperature, sea and sunshine in September: long-term averages from 30 years of weather data, not a forecast.
Holiday weather in September
Excellent
Best time to visit: August – May
What is the weather like in Buenos Aires in September?
In September, Buenos Aires is mild: daytime highs average 17 °C, and nights cool down to about 11 °C. The sea averages 15.6 °C – swimming is only for the hardy. The sun shines for around 7 hours a day. Rain falls on about 6 days, adding up to 67 mm. All in all, September is an excellent month for a holiday in Buenos Aires.
September compared
How the weather changes from August to October. Tap a month to open it.
| AugustAug | SeptemberSep | OctoberOct | |
|---|---|---|---|
| Score | 76 | 87 | 86 |
| Day | 16° | 17° | 21° |
| Night | 9° | 11° | 13° |
| Sea | 14° | 16° | 19° |
| Sun | 7 h | 7 h | 8 h |
| Rain days | 6 | 6 | 9 |
More details for September
- Daylight
- 11 h 50 min06:54 – 18:44
- UV index
- 6 · highclear sky, noon (estimate)
- Muggy days
- 0 daysdew point 18 °C or more
- Wind
- 21 km/haverage daily peak
- Cloud cover
- 51 %on average
- Hot days
- 0 days30 °C or more
- Time zone
- UTC−3America/Argentina/Buenos_Aires
How the score comes together
- Temperatureweight 50 %94 %
- Sunshineweight 20 %73 %
- Few rainy daysweight 30 %84 %
Each factor is rated from 0 to 100 % and weighted for the travel style “City break”.
What to pack in September
- Sunscreen
- Sunglasses & sun hat
- A jumper for the evenings
Buenos Aires in September: quick answers
Is Buenos Aires hot in September?
No. In September, Buenos Aires is mild: daytime highs average 17 °C and nights drop to about 11 °C.
Can you swim in Buenos Aires in September?
Only if you don't mind cold water: in September the sea averages just 15.6 °C. Comfortable swimming is possible from November to April.
Does it rain much in Buenos Aires in September?
Rain falls on about 6 days, adding up to 67 mm.
Buenos Aires month by month
The whole year in Buenos AiresAll destinations: Argentina
Climate averages 1996–2025, not a forecast. Data: Copernicus ERA5 / ERA5-Land via Open-Meteo.com (CC BY 4.0), NOAA OISST, GeoNames (CC BY 4.0)