Rio de Janeiro Weather in September
Rio de Janeiro in September averages 27°C (81°F) during the day and 19°C (66°F) at night. Keep in mind that quite a bit of rainfall is expected this month.
Rainfall in Rio de Janeiro in September
The climate data from previous years indicates about 12 days of rain, averaging 85 mm (3.3 in) for the month. Individual showers can be quite heavy this month. A proper umbrella or rain jacket is worth having.
Temperature in Rio de Janeiro in September
If you're visiting Rio de Janeiro in September, expect perfect temperatures with highs of 27°C (81°F) and overnight lows of 19°C (66°F). This gives the month a fairly typical daily rhythm, with warmer afternoons and more comfortable nights. Nights drop to around 19°C (66°F), which is noticeably cooler than the daytime. A light jacket for the evening is a sensible addition, and the cool nights tend to make sleeping comfortable.
Sunshine in Rio de Janeiro in September
The city usually sees around 144 hours of sunlight, indicating a moderately sunny period.
Wind Speed in Rio de Janeiro in September
Wind speeds average 3 m/s (6 knots) during September. At this speed, light breezes keep leaves and small twigs in gentle motion while the wind also provides natural cooling. Since this is an average, some days are more tranquil while others have more persistent light winds that are more noticeable.
Average water temperature in September
The water is 21°C (70°F) this month — a comfortable temperature that most swimmers enjoy. Warm enough to stay in without getting cold quickly.Our weather planner can help you find worldwide destinations with pleasant weather during this period. May, June, July, August and September typically offer the best weather for Rio de Janeiro.
Check the conditions for any month of the year.
For a detailed overview over the year and the best time to visit Brazil, check out our Rio de Janeiro's climate page.
Rio de Janeiro Temperature in September
Min Temperature
19°C (66°F)
Max Temperature
27°C (81°F)
Water Temperature
21°C (70°F)
Chance of Rain
38%
Precipitation
85 mm (3.3 in)
Rainy days
12 days
Humidity
79%
Windspeed
3 m/s (6 knots)
Sunshine
144 hours
Percentage Sunshine
Daily Historical Temperatures
50-year average (1976-2025)
Based on our historical records, temperatures in Rio de Janeiro typically stay consistent throughout September, with daily highs averaging around 27°C (81°F). Nights are pleasant, with lows around 19°C (66°F).
Average temperatures in September
Daily Historical Precipitation
50-year average (1976-2025)
Average daily rainfall for each day of the month based on long-term records.
Average precipitation in September
Historical weather for Rio de Janeiro in September
Browse day-by-day weather records for Rio de Janeiro spanning 51 years. Select any month and year to see actual temperatures, rainfall, and conditions recorded on each day.
Rio de Janeiro historical weather extremes in September
Based on 49 years of weather observations (1976-2025), these are the most extreme conditions recorded in Rio de Janeiro.
- On September 13, 1988, temperatures climbed to 41°C (106°F), marking the warmest September day on record.
- The coldest September day was on September 18, 1980, with a maximum of 18°C (64°F).
- Nighttime temperatures dropped to 12°C (54°F) on September 19, 1979, marking the coldest September night on record.
Best Places in Brazil in September
Find out more about the weather in Brazil and which places have the best travel conditions in this month. See all of Brazil in September →
perfect weather
pleasant
tolerable
unpleasant
poor
What to Wear in Rio de Janeiro in September
Warm but pleasant conditions in Rio de Janeiro in September. Focus on lightweight, maybe with natural fabrics, cotton blend shirts, comfortable shorts, and breathable footwear. A light cover-up for sun protection is smart too. Expect heavy rainfall, so bring good rain protection and waterproof bags. With water temperatures around 21°C (70°F), swimming conditions are excellent. Pack your swimsuit, goggles, and maybe some water shoes. Sunglasses could come in handy during the sunnier parts of your trip.What To Do in Rio de Janeiro in September
We rated the following activities from 1 (least suitable) to 10 (best) to do.
Check the conditions for any month of the year.
For a detailed overview over the year and the best time to visit Brazil, check out our Rio de Janeiro's climate page.
Temperature Rainfall Sunshine Humidity Wind Speed Water Temp
See the full Rio de Janeiro climate overview or explore weather in Brazil.
