Rio de Janeiro weather in September
Rio de Janeiro averages 26°C by day and 20°C at night in September, with the sea at 23°C and about 59 mm of rain in the month.
Day
26°C
Night
20°C
Sea
23°C
Rain
59 mm
Flight from London
11½h
What September feels like
September is hot in Rio de Janeiro: proper beach weather.
The sea is 23°C: fine for swimming without a wetsuit.
Rain is occasional: about 59 mm in the month.
That is 7°C warmer than an average September day in London.
Of the 56 sun destinations we track, Rio de Janeiro is the #49 warmest in September.
Want it warmer in September?
These are hotter than Rio de Janeiro this month for at most an hour and a half more flying:
Rio de Janeiro weather by month
September is highlighted. Compare with August and October, or see the full year in Rio de Janeiro.
| Month | Day | Night | Sea | Rain |
|---|---|---|---|---|
| January | 30°C | 24°C | 26°C | 154 mm |
| February | 30°C | 24°C | 28°C | 126 mm |
| March | 29°C | 24°C | 26°C | 133 mm |
| April | 27°C | 22°C | 25°C | 86 mm |
| May | 26°C | 20°C | 24°C | 59 mm |
| June | 25°C | 19°C | 23°C | 38 mm |
| July | 25°C | 18°C | 22°C | 40 mm |
| August | 25°C | 18°C | 22°C | 63 mm |
| September | 26°C | 20°C | 23°C | 59 mm |
| October | 27°C | 21°C | 22°C | 89 mm |
| November | 27°C | 21°C | 23°C | 130 mm |
| December | 29°C | 23°C | 25°C | 132 mm |
Rio de Janeiro in September: quick answers
Is Rio de Janeiro hot in September?
September is hot in Rio de Janeiro: proper beach weather. Average highs are 26°C and lows 20°C.
Can you swim in Rio de Janeiro in September?
The sea is 23°C: fine for swimming without a wetsuit.
Does it rain in Rio de Janeiro in September?
Rain is occasional: about 59 mm in the month.
What is the warmest month in Rio de Janeiro?
February, at an average high of 30°C. The coolest is July at 25°C.
How long is the flight to Rio de Janeiro from the UK?
About 11½h direct from London, estimated from the 9,260 km distance. Check your airline for exact times.
Still choosing? See where is hot in September for every destination ranked by temperature, sea and flight time.
How we measured this
Averages of every day in September from 2016 to 2025, from the Open-Meteo historical weather archive (ECMWF ERA5 reanalysis). Sea temperature is the 2023 to 2025 average from the Open-Meteo marine archive. Rain is the average monthly total. Reanalysis describes an area about 25 km across, so sheltered resorts can run a degree or two warmer. Flight time is a distance-based estimate from London Heathrow.
Planning Rio de Janeiro in September?
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