Rio Branco weather in August

In August, Rio Branco sees average daytime highs of 33°C and overnight lows near 20°C, with 38 mm of rain across 6.3 wet days and about 11.7 hours of daylight. It is the 2nd-warmest and 10th-wettest month of the year here.

Day-to-day highs hold fairly steady near 33°C through the month. The sky is clear or mostly clear about 56% of the time in August, and the air most often feels oppressive.

Daylight stretches from about 11 h 36 min at the start of August to 11 h 48 min by month's end. Set against the rest of the year, August is Rio Branco's 2nd-clearest and 1st-windiest month. For the whole year in context, see Rio Branco's year-round climate.

Daytime high
33°
2nd warmest
Overnight low
20°
3rd coldest
Rainfall
38 mm
6.3 wet days
Daylight
11 h 42 min
5:45 AM – 5:25 PM
Cloud cover
41%
2nd clearest
Wind
6 km/h
1st windiest
Solar energy
5.31 kWh/m²
Travel score
4.0
out of 10

Rio Branco is human settlement in Acre, Brazil.

Founded
1882

Air quality: WHO Ambient Air Quality Database. Density & description: Wikidata (CC0), GeoNames.

Temperature in August

Average highAverage lowShaded bands: 10–90% of days

Day-to-day highs hold fairly steady near 33°C through the month.

A typical August day in Rio Branco reaches about 33°C in the afternoon and slips back to 20°C overnight — a 13°C spread between the day's warmth and the night's chill. On most days the high lands between 29°C and 36°C. Set against its neighbours, August runs about 2°C warmer than July and on par with September.

15°20°25°30°35°40°151015202531
Avg high (°C)Avg low (°C)
13220
23320
33320
43320
53320
63320
73320
83320
93320
103320
113320
123320
133320
143320
153320
163320
173320
183321
193321
203321
213321
223321
233321
243321
253321
263321
273321
283321
293321
303321
313321

How August really feels in Rio Branco

Once humidity and wind are folded in, August averages 31 days that feel above 32°C and 0 that feel at or below 0°C — the comfort signal a plain temperature reading hides.

Days feeling ≥ 32°C
31
heat index over the day's high
Days feeling ≤ C
0
wind chill below the day's low

The story in August is heat — humidity pushes the afternoon "feels like" well above the raw temperature.

Rio Branco weather by month

How August compares with the rest of the year at a glance. August is the 2nd-warmest and 10th-wettest month here — the current month is highlighted below.

MonthHigh / Low (°C)Rainfall (mm)Wet daysDaylight (hours)Travel score
Jan30° / 23°25527.712.52.8
Feb30° / 23°2402512.32.8
Mar30° / 23°24927.212.12.8
Apr30° / 22°16022.811.83.2
May30° / 21°7615.411.54.3
Jun30° / 20°306.811.45.3
Jul31° / 20°214.211.55.1
Aug33° / 20°386.311.74.0
Sep33° / 22°7611.911.93.2
Oct33° / 23°13719.512.22.8
Nov31° / 23°19922.912.52.8
Dec30° / 23°24626.312.62.9

Cloud cover in August

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 56% of the time in August.

Beyond those clear spells, partly cloudy skies cover about 19% of August, with mostly cloudy or overcast conditions the remaining 25%. Skies tend to cloud over as the month goes on.

0%25%50%75%100%151015202531
Clearer (%)Cloudier (%)
18119
28119
38020
48020
57921
67921
77921
87921
97921
107822
117822
127723
137723
147624
157624
167624
177525
187525
197525
207426
217426
227426
237228
247228
257228
267030
277030
287030
296832
306832
316832

Chance of precipitation in August

Any precipitation

Rio Branco gets around 38 mm of rain over 6.3 wet days in August. The line is the day-by-day chance of measurable precipitation.

Day to day, the chance of measurable rain averages around 21% and peaks near 28% on the wettest days. The odds climb toward the end of the month.

0%10%20%30%40%151015202531
Rain chance (%)
112
212
312
413
513
614
714
815
916
1017
1118
1219
1320
1421
1522
1622
1723
1823
1924
2024
2125
2225
2326
2426
2526
2627
2727
2827
2928
3028
3128

Humidity in August

DryComfortableHumidMuggyOppressiveMiserable

Most of August feels oppressive — the stacked bands show each day's mix of comfort levels, read off the dew point.

By dew point, August lands in the oppressive band about 47% of days. Sticky, muggy-or-worse air turns up on roughly 76% of them.

0%25%50%75%100%151015202531
Dry (%)Comfortable (%)Humid (%)Muggy (%)Oppressive (%)
156193832
256193733
356203733
455203634
555203535
655203536
755193437
855193338
955193239
1055183141
1155183142
1255173043
1355173044
1455162945
1555162946
1645152947
1745142948
1845132949
1945122851
2046112851
2146112752
2246102753
2336102655
2436102556
253692458
263692458
273592360
283592261
293582163
303582064
313581965

Wind in August

Winds average 6 km/h in August, the windiest month of the year.

Across August, daily wind ranges from about 6 km/h on the calmest days to 6 km/h at its breeziest. It stays fairly steady from day to day.

0246810151015202531
Wind speed (km/h)Feels
16calm
26calm
36calm
46calm
56calm
66calm
76calm
86calm
96calm
106calm
116calm
126calm
136calm
146calm
156calm
166calm
176calm
186calm
196calm
206calm
216calm
226calm
236calm
246calm
256calm
266calm
276calm
286calm
296calm
306calm
316calm

Sunrise & sunset in August

DaylightNight

Daylight runs from about 11 h 36 min at the start of August to 11 h 48 min by month's end. The lit band spans sunrise to sunset each day.

Days grow by about 12 minutes over August. Sunrise moves from 5:51 AM to 5:37 AM, and sunset from 5:24 PM to 5:25 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202531
Daylight (h)Sunrise (AM)Sunset (PM)
111.65:515:24
211.65:505:24
311.65:505:24
411.65:505:24
511.65:495:25
611.65:495:25
711.65:495:25
811.65:485:25
911.65:485:25
1011.65:485:25
1111.65:475:25
1211.65:475:25
1311.65:475:25
1411.75:465:25
1511.75:465:25
1611.75:455:25
1711.75:455:25
1811.75:445:25
1911.75:445:25
2011.75:435:25
2111.75:435:25
2211.75:425:25
2311.75:425:25
2411.75:415:25
2511.75:415:25
2611.85:405:25
2711.85:405:25
2811.85:395:25
2911.85:395:25
3011.85:385:25
3111.85:375:25

Solar energy in August

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in August, about 5.31 kWh/m².

For context, solar energy here swings from a low near 4.25 kWh/m² to a high of 5.57 kWh/m² in September across the year — August's 5.31 kWh/m² sits near the top of that range.

0246151015202531
Solar energy (kWh/m²)Level
15.1Bright
25.1Bright
35.2Bright
45.2Bright
55.2Bright
65.2Bright
75.2Bright
85.2Bright
95.2Bright
105.2Bright
115.2Bright
125.3Bright
135.3Bright
145.3Bright
155.3Bright
165.3Bright
175.3Bright
185.3Bright
195.3Bright
205.3Bright
215.3Bright
225.4Bright
235.4Bright
245.4Bright
255.4Bright
265.4Bright
275.4Bright
285.4Bright
295.5Bright
305.5Bright
315.5Bright
Planning a trip in August

Hazard calendar for Rio Branco

In seasonPeak

None of Rio Branco's seasonal hazards are active in August. The full-year calendar below shows when the rainy season, cyclone risk and dust haze do peak.

Rio Branco's rainy season runs October–April, when most of the year's rain falls.

Rainy season
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec

Is August a good time to visit Rio Branco?

Our two travel scores rate August for general sightseeing and for beach or pool weather — 0 (poor) to 10 (ideal).

4.0
Sightseeing
4th-best month of the year
7.0
Beach & pool
3rd-best month of the year

August is a reasonable time to visit Rio Branco for sightseeing. The water and warmth also suit a beach or pool day.

What to pack for Rio Branco in August

From August's temperature range, rain chance, sun and wind — what's worth putting in the bag.

In August, Rio Branco sees daytime highs around 33°C and nights near 20°C. Pack light clothes. Worth having: sun protection. About 6 days see rain.

light clothessun protection

UV index in Rio Branco in August

LowModerateHighVery highExtreme

Clear-sky midday UV in August peaks around 7 — enough to warrant sun protection. The full-year curve, shaded by WHO exposure level, is below.

Under clear skies, the midday UV index in Rio Branco peaks around January 20 at about 15 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near September 12 at about 5 (moderate).

The index reaches 3 or more — the level where the WHO recommends sun protection — every month of the year.

025710JanFebMarAprMayJunJulAugSepOctNovDecExtremeVery highHighExtremeJan 20UV 15Sep 12UV 5
UV index (midday)Level
Jan15Extreme
Feb15Extreme
Mar14Extreme
Apr13Extreme
May11Extreme
Jun9Very high
Jul8Very high
Aug7High
Sep4Moderate
Oct12Extreme
Nov13Extreme
Dec13Extreme

Air quality in Rio Branco in August

GoodModeratePoorUnhealthyVery unhealthy

Average fine-particle pollution (PM2.5) through the year — so you can see where August falls, not just the annual average.

Air quality in Rio Branco is worst in September — around 100 µg/m³ PM2.5 (unhealthy), about 12.4× the cleanest month (June, 8 µg/m³).

Modeled monthly averages (CAMS reanalysis, 2015–2024).

0306090120JanFebMarAprMayJunJulAugSepOctNovDecModerateGoodModerateUnhealthyModerateGoodSep 1394 µg/m³Jun 98 µg/m³
PM2.5 (µg/m³)Level
Jan13Moderate
Feb13Moderate
Mar13Moderate
Apr10Good
May8Good
Jun8Good
Jul14Moderate
Aug65Unhealthy
Sep100Unhealthy
Oct27Moderate
Nov13Moderate
Dec11Good
Location & terrain

Where is Rio Branco?

Rio Branco sits at 10.0°S, 67.8°W, 153 m above sea level, in Brazil. The nearest listed city is Senador Guiomard, 21 km away.

Topography around Rio Branco

How much the land rises and falls, and what covers it, within 3, 16 and 80 km of Rio Branco.

Within 3 km, the terrain around Rio Branco has only modest variations in elevation — a maximum elevation change of 50 m around an average of 142 m above sea level; within 16 km, only modest variations in elevation — a maximum elevation change of 103 m; within 80 km, only modest variations in elevation — a maximum elevation change of 165 m.

The land around Rio Branco is covered by artificial surfaces (54%) and trees (33%) within 3 km, trees (46%) and grassland (46%) within 16 km, and trees (61%) and grassland (38%) within 80 km.

3 km
50 m
16 km
103 m
80 km
165 m
treesgrasslandartificial surfaceswater
August weather nearby: Senador Guiomard 21 km · Porto Acre 53 km · Plácido de Castro 79 km · Xapuri 107 km · Sena Madureira 139 km · Boca do Acre 143 km · Brasiléia 155 km · Epitaciolândia 155 km

Brazil travel facts

Travel advisory
Level 2
Exercise Increased Caution
Power plugs
Type C / N
127 / 220 V · 60 Hz
Prices
≈ 46% of US
price level, 2025
GDP per capita
$10,713
2025
Happiness
6.6 / 10
World Happiness, 2025
Safe drinking water
89%
of population, 2024
Homicide rate
19.3
per 100k, 2023
Road deaths
16
per 100k/yr, 2019
Income group
Upper middle
World Bank
English
Low
EF EPI 482
Religion
Roman Catholic 57%Evangelical 27%none 9%other 4%

Sources: World Bank, US State Department, World Happiness Report, WHO/UNICEF, EF EPI, CIA World Factbook.

Data sources

Temperature, precipitation, cloud, humidity, wind and solar figures are a 1991–2020 climatology for Rio Branco (-9.9747°, -67.81°, elevation 153 m), computed from hourly ERA5 reanalysis — contains modified Copernicus Climate Change Service information. Sun figures are astronomical calculations, not observations. City data © GeoNames, CC BY 4.0. Map outlines from Natural Earth (public domain); interactive map © Google. UV index is derived from CAMS (Copernicus Atmosphere Monitoring Service) clear-sky UV data — contains modified Copernicus Atmosphere Monitoring Service information. Monthly air-quality (PM2.5) seasonality is from the CAMS EAC4 reanalysis (Copernicus Atmosphere Monitoring Service), scaled to the WHO annual mean where available. Topography is sampled from the Copernicus DEM GLO-90 elevation model (© ESA/Airbus) and ESA WorldCover 2021 land cover (CC BY 4.0).