Rio Branco climate

Name: Rio Branco
Address: BR

Rio Branco is warmest in September, with average highs of 32 °C, and coldest in July, when nights average 20 °C. December is the wettest month (254 mm) and July the driest (23 mm). Figures are 1991–2020 climate normals.

Across a full year Rio Branco averages 1,754 mm of rain and 358 days above 25 °C.

Brazil · population 419,452 · 1991–2020 normals

Temperature below 0 °C to above 30 °C Rain band height is that month’s share of the wettest month

Warmest month September 32 °C
Coldest month July 20 °C
Driest month July 23 mm
Wettest month December 254 mm
Least cloud July 37 % cloud
Hottest on record September 38 °C
Coldest on record July 12 °C

What to expectRio Branco through the year

Rio Branco changes little through the year. Average daily highs stay between 30 and 32 °C, so no month stands out as a season in the way it would further from the equator.

Counted across a normal year, 358 days a year reach 25 °C, 179 of them reach 30 °C. The warmest reading in the 1991–2020 record is 38 °C, in September.

Rain is strongly seasonal. December averages 254 mm against 23 mm in July — 11 times as much. Planning around the dry months matters more here than planning around temperature.

Month by month

Month	Avg high	Rainfall	Cloud
January	29.4 °C	250 mm	90 %
February	29.2 °C	242 mm	91 %
March	29.2 °C	249 mm	90 %
April	29.0 °C	164 mm	85 %
May	28.5 °C	81 mm	71 %
June	28.9 °C	34 mm	53 %
July	30.4 °C	23 mm	37 %
August	32.1 °C	40 mm	40 %
September	32.4 °C	77 mm	58 %
October	31.5 °C	138 mm	76 %
November	30.1 °C	201 mm	85 %
December	29.5 °C	254 mm	88 %

Temperature month by month

Month	Avg high	Avg low	Mean	Record high	Record low	Days above 25 °C	Days above 30 °C
January	29.4 °C	23.0 °C	25.4 °C	32.9 °C	20.6 °C	31	12
February	29.2 °C	22.9 °C	25.3 °C	33.0 °C	20.4 °C	28	10
March	29.2 °C	22.8 °C	25.2 °C	32.3 °C	19.8 °C	31	10
April	29.0 °C	22.5 °C	25.0 °C	33.9 °C	15.9 °C	29	8
May	28.5 °C	21.7 °C	24.4 °C	32.0 °C	14.8 °C	29	5
June	28.9 °C	20.9 °C	24.3 °C	33.0 °C	12.9 °C	28	9
July	30.4 °C	20.4 °C	24.8 °C	35.5 °C	12.4 °C	30	20
August	32.1 °C	21.4 °C	26.2 °C	36.6 °C	12.7 °C	31	26
September	32.4 °C	22.6 °C	26.7 °C	37.6 °C	14.5 °C	30	25
October	31.5 °C	23.1 °C	26.5 °C	37.5 °C	18.4 °C	31	23
November	30.1 °C	22.9 °C	25.8 °C	35.1 °C	15.4 °C	30	16
December	29.5 °C	23.0 °C	25.5 °C	33.0 °C	18.7 °C	31	13

Rain, sun and wind month by month

Month	Rainfall	Wet days	Daylight	Cloud cover	Humidity	Wind
January	250 mm	27	13 h/day	90 %	89 %	9.7 km/h
February	242 mm	25	12 h/day	91 %	90 %	9.1 km/h
March	249 mm	27	12 h/day	90 %	90 %	8.5 km/h
April	164 mm	23	12 h/day	85 %	90 %	8.6 km/h
May	81 mm	15	12 h/day	71 %	88 %	8.6 km/h
June	34 mm	7	12 h/day	53 %	84 %	8.6 km/h
July	23 mm	4	12 h/day	37 %	75 %	9.2 km/h
August	40 mm	6	12 h/day	40 %	70 %	9.6 km/h
September	77 mm	11	12 h/day	58 %	75 %	9.7 km/h
October	138 mm	19	12 h/day	76 %	82 %	9.2 km/h
November	201 mm	22	13 h/day	85 %	87 %	9.4 km/h
December	254 mm	26	13 h/day	88 %	89 %	9.7 km/h

Where Rio Branco ranks

Ranking	Position	Value
The warmest places in South America in August	37th of 50	32 °C
The warmest places in South America in September	37th of 50	32 °C
The warmest places in South America in July	39th of 50	30 °C
The warmest places in South America in October	42nd of 50	32 °C
The warmest places in South America in November	48th of 50	30 °C

Planning a trip? See the best time to visit Rio Branco.

QuestionsCommon questions about Rio Branco’s climate

When is the best time to visit Rio Branco?

That depends on what you want, so the honest answer is a comparison rather than a single month. May, June, July sit closest to 20 °C on average, September is the warmest month and July the driest. The month-by-month table above has the full picture.

How hot does Rio Branco get?

In September, the warmest month, daily highs average 32 °C. About 179 days a year pass 30 °C. The highest value in the 1991–2020 record is 38 °C.

How cold does it get in winter?

Nights average 20 °C in July, the coldest month. Freezing nights are not part of a normal year here.

Which month is wettest in Rio Branco?

December, averaging 254 mm over 26 days with rain. The driest month is July with 23 mm. The year as a whole averages 1,754 mm.

Are these figures a forecast?

No. They are 1991–2020 climate normals: the average of thirty years, which describes what a month is usually like in Rio Branco rather than what any particular week will bring. Individual years can differ substantially from the normal.

Data sources and method

ERA5 / ERA5-Land reanalysis — Copernicus Climate Change Service (C3S), ECMWF. Copernicus Licence
Open-Meteo — Open-Meteo.com. CC BY 4.0
NOAA OISST v2.1 — NOAA Physical Sciences Laboratory. Public domain
GeoNames — GeoNames.org. CC BY 4.0

Normal period: 1991–2020
Data point: -9.975°, -67.810° (the coordinates the reanalysis values are taken for)
Dataset version: era5-1991-2020-scores1.1
Last processed: 1 August 2026

Measured values come from ERA5 reanalysis and are reproduced unchanged. Calculated by us: monthly rankings, daylight hours, beach and comfort scores. Full formulas are on the methodology page.

Contains modified Copernicus Climate Change Service information 2026. Neither the European Commission nor ECMWF is responsible for any use that may be made of the Copernicus information or data it contains.