Rio de Janeiro 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
Good
Best time to visit: January – December
What is the weather like in Rio de Janeiro in September?
In September, Rio de Janeiro is hot: daytime highs average 28 °C, and nights cool down to about 18 °C. The sea averages 21.4 °C – refreshing for a swim. The sun shines for around 7 hours a day. Rain is frequent, with about 9 rainy days and 57 mm in total. On about 10 days the thermometer climbs to 30 °C or more. All in all, September is a good month for a holiday in Rio de Janeiro.
September compared
How the weather changes from August to October. Tap a month to open it.
| AugustAug | SeptemberSep | OctoberOct | |
|---|---|---|---|
| Score | 81 | 75 | 73 |
| Day | 26° | 28° | 28° |
| Night | 17° | 18° | 20° |
| Sea | 21° | 21° | 22° |
| Sun | 7 h | 7 h | 6 h |
| Rain days | 7 | 9 | 12 |
More details for September
- Daylight
- 11 h 56 min05:50 – 17:46
- UV index
- 9 · very highclear sky, noon (estimate)
- Muggy days
- 11 daysdew point 18 °C or more
- Wind
- 18 km/haverage daily peak
- Cloud cover
- 54 %on average
- Hot days
- 10 days30 °C or more
- Time zone
- UTC−3America/Sao_Paulo
How the score comes together
- Temperatureweight 35 %100 %
- Seaweight 25 %63 %
- Sunshineweight 20 %62 %
- Few rainy daysweight 20 %61 %
Each factor is rated from 0 to 100 % and weighted for the travel style “Sun, sea & sand”.
What to pack in September
- Swimwear
- Sunscreen
- Sunglasses & sun hat
- Light, breathable clothes
- Water bottle – drink plenty
- Rain jacket or umbrella
Rio de Janeiro in September: quick answers
Is Rio de Janeiro hot in September?
Yes. In September, Rio de Janeiro is hot: daytime highs average 28 °C and nights stay around 18 °C. On about 10 days the thermometer climbs to 30 °C or more.
Can you swim in Rio de Janeiro in September?
Yes. In September the sea averages 21.4 °C – refreshing for a swim.
Does it rain much in Rio de Janeiro in September?
Rain is frequent, with about 9 rainy days and 57 mm in total.
Rio de Janeiro month by month
The whole year in Rio de JaneiroAll destinations: Brazil
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)