Rio de Janeiro Weather in September
Brazil · Tropical climate · Data averaged from 2020-01-01 to 2024-12-31 (5 years)
September in Rio de Janeiro sees average temperatures ranging from a low of 19.9°C (67.8°F) to a high of 26.7°C (80.1°F), with a mean of 22.9°C (73.2°F). Compared to the annual average of 23.6°C (74.5°F), this month is 0.7°C cooler than the yearly norm. Precipitation averages 70.0mm, making it approximately 26.0mm drier than the monthly average of 96.0mm. The city receives an average of 10.0 hours of sunshine per day during September, with relative humidity averaging 79.1%. Wind speeds reach an average maximum of 18.8 km/h. For travelers, this month offers a temperature experience in Rio de Janeiro, with drier-than-average conditions compared to the rest of the year.
Rio doesn't have seasons the way Northern Hemisphere cities do — it has rhythms. I spent Carnival there once and the energy is indescribable, but the heat and crowds aren't for everyone. The data shows March-May as the sweet spot: still warm, less humid, fewer tourists. What the numbers can't capture is the late afternoon light on Ipanema — that's when Rio feels most itself. December-February is festive but exhausting; pace yourself.
September vs Adjacent Months
| Metric | August | September | October |
|---|---|---|---|
| Mean Temp | 21.3°C (70.3°F) | 22.9°C (73.2°F) | 23.2°C (73.8°F) |
| Rainfall | 74.0mm | 70.0mm | 101.5mm |
| Sunshine | 9.3 hrs | 10.0 hrs | 9.1 hrs |
| Humidity | 77.9% | 79.1% | 83.1% |
| Wind | 17.8 km/h | 18.8 km/h | 19.1 km/h |
| Rainy Days | 11.2 | 12.4 | 21.8 |
Seasonal Context
September falls in Autumn in the Northern Hemisphere. Autumn sees temperatures gradually cooling from summer highs. For travelers visiting Rio de Janeiro in September, the data indicates favorable conditions based on the combination of temperature, precipitation, and daylight hours.
Frequently Asked Questions
What is the average temperature in Rio de Janeiro in September?
The average temperature in Rio de Janeiro during September ranges from 19.9°C (67.8°F) to 26.7°C (80.1°F), with a mean of 22.9°C (73.2°F).
How much does it rain in Rio de Janeiro in September?
Rio de Janeiro receives an average of 70.0mm of precipitation in September, spread across approximately 12.4 rainy days.
What should I pack for Rio de Janeiro in September?
Based on September weather data, pack layers including light jackets and t-shirts, plus an umbrella.
Is September a good time to visit Rio de Janeiro?
September is a good time to visit Rio de Janeiro, with comfortable temperatures and manageable rainfall.
Other Months for Rio de Janeiro
Cities with Similar September Climate (Tropical)
Data Source: Open-Meteo historical archive (2020-01-01 to 2024-12-31). Daily measurements aggregated into monthly climate normals. Coordinates: -22.91°, -43.17°. Timezone: America/Sao_Paulo. Last updated: 2026-07-30.