Rio de Janeiro in September
In September, Rio de Janeiro has a daily low of 18.3 °C (64.9 °F), as 1991-2020 model estimates; figures in brackets are converted. There is no data for the daily high: Not published: the city's cell is sea, and a moved cell failed our station test. There is no data for rain: Not published: the model failed our station test in tropical cities.
Last updated : first sourced version.
Best time to visit Rio de Janeiro: September: no data: no daily high to test against our rule. Expect days that grow by 38 min.
What September is like in Rio de Janeiro
- From late July to late September, samba schools choose the song for the next Carnival. Fans pack the halls for long nights of samba finals. Source: Riotur (Rio city tourism), checked .
- On 27 September, the day of Saints Cosmas and Damian, the MUHCAB museum of Afro-Brazilian culture hands out bags of sweets to children. Source: Riotur (Rio city tourism), checked .
- From June to November, Rio's ipê trees flower, purple and pink, then yellow and white. The parks office lists some on Praça Ben Gurion in Laranjeiras. Source: Diário do Rio, on the city parks foundation's ipê list, checked .
- On 27 September, by the São Cosme e São Damião church in Andaraí, a woman with a bag calls out "Who wants sweets?" Source: Agência Brasil (EBC), checked .
Key figures
Weather in September, 1991-2020 model estimates
- Daily high
- no data
- Daily low
- 18.3 °C (64.9 °F)
- Rain
- no data
- Sunshine
- no data
Model estimate 1991-2020, not a weather station: ERA5-Land model estimates (Copernicus), computed by City by Month for the grid cell nearest the city. Licence: CC BY 4.0. Checked . How we make and test model estimates
Model estimate for the ERA5-Land grid cell at 22.9° S, 43.3° W, 10 km from the city centre point; the city's own cell is sea, so this is the nearest land cell.
How we define and convert these figures
Notes. Daily high: Not published: the city's cell is sea, and a moved cell failed our station test. Rain: Not published: the model failed our station test in tropical cities. Sunshine: Not in our ERA5-Land estimates.
Daylight on 15 September 2026
- Sunrise
- 05:49 local time
- Sunset
- 17:47 local time
- Day length
- 11 h 57 min
Day length 1-30 September: 11 h 39 min to 12 h 17 min, +38 min.
Source: NOAA Solar Calculator equations, checked .
Month by month
Each month: daily high: no data, 1991-2020 model estimates. Rain: no data.
ERA5-Land model estimates 1991-2020, as above, checked .
This month against the year
| Measure | September | Rank |
|---|---|---|
| Daily high | no data | no data |
| Daily low | 18.3 °C | 4th coldest |
| Rain | no data | no data |
| Sunshine | no data | no data |
| Day length | 11 h 57 min | 6th shortest |
Equal values share a rank. How we rank months
ERA5-Land model estimates 1991-2020, as above, checked .
Day length: NOAA solar equations, checked .
Public holidays this month
| Date | Holiday |
|---|---|
| Monday | Independence Day legis.sigepe.gov.br |
Typed from the official list and re-checked, .
September 2027: no data. No official 2027 list found.
English names are from the holidays library where the official list gives none. How we check holidays
Source: Official public holiday list (tjrj.jus.br), checked ; holidays Python library, checked . Library: holidays 0.105.
Same month in other cities
No daily high for Rio de Janeiro, so it is not compared with other cities.
Sources
- Attribution: Copernicus Climate Change Service (2025): ERA5 Land hourly time-series data from 1950 to present. Copernicus Climate Change Service (C3S) Climate Data Store (CDS). DOI: 10.24381/ee82e357. Accessed on the check date shown. Generated using or contains modified Copernicus Climate Change Service information 2025. Neither the European Commission nor ECMWF is responsible for any use that may be made of the Copernicus information or data it contains. Licence: CC BY 4.0. Checked .
- NOAA Solar Calculator equations, computed locally, NOAA Global Monitoring Laboratory (method); City by Month (computation). Attribution: Computed with the NOAA Solar Calculator method (no NOAA endorsement implied). Licence: Method, not data. Checked .
- holidays Python library, run locally. Attribution: holidays library, Vacanza team. Licence: MIT. Checked .
Official sources
- Official public holiday list (tjrj.jus.br). Checked .
Cite this page: City by Month. "Rio de Janeiro in September: weather, daylight, holidays". https://citybymonth.com/cities/brazil/rio-de-janeiro/september/. Last updated 8 November 2026.