Rio das Ostras weather in August

In August, Rio das Ostras sees average daytime highs of 26°C and overnight lows near 18°C, with 34 mm of rain across 6.3 wet days and about 11.2 hours of daylight. It is the 10th-warmest and 10th-wettest month of the year here.

Day-to-day highs hold fairly steady near 26°C through the month. The sky is clear or mostly clear about 49% of the time in August, and the air most often feels humid.

Daylight stretches from about 11 hours at the start of August to 11 h 30 min by month's end. Set against the rest of the year, August is Rio das Ostras's 3rd-clearest and 3rd-windiest month. For the whole year in context, see Rio das Ostras's year-round climate.

Daytime high
26°
10th warmest
Overnight low
18°
3rd coldest
Rainfall
34 mm
6.3 wet days
Daylight
11 h 12 min
7:15 AM – 6:28 PM
Cloud cover
44%
3rd clearest
Wind
12 km/h
3rd windiest
Solar energy
4.38 kWh/m²
Travel score
7.6
out of 10

Rio das Ostras is human settlement in Brazil.

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 26°C through the month.

A typical August day in Rio das Ostras reaches about 26°C in the afternoon and slips back to 18°C overnight — a 8°C spread between the day's warmth and the night's chill. On most days the high lands between 22°C and 30°C. Set against its neighbours, August runs on par with July and on par with September.

15°20°25°30°35°151015202531
Avg high (°C)Avg low (°C)
12518
22518
32518
42518
52518
62618
72618
82618
92618
102618
112618
122618
132618
142618
152618
162618
172618
182618
192618
202618
212618
222618
232618
242618
252618
262618
272618
282618
292618
302619
312619

How August really feels in Rio das Ostras

Once humidity and wind are folded in, August averages 0 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
0
heat index over the day's high
Days feeling ≤ C
0
wind chill below the day's low

August sits comfortably in between — no days that feel dangerously hot or drop to a hard freeze once humidity and wind are folded in.

Rio das Ostras weather by month

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

MonthHigh / Low (°C)Rainfall (mm)Wet daysDaylight (hours)Travel score
Jan30° / 23°20616.613.24.1
Feb31° / 24°13612.712.84.2
Mar30° / 23°17217.812.24.3
Apr28° / 21°851211.55.7
May26° / 19°609.510.96.9
Jun26° / 18°315.910.67.6
Jul25° / 18°295.610.87.8
Aug26° / 18°346.311.27.6
Sep26° / 19°7310.111.96.7
Oct27° / 20°1081212.56.1
Nov27° / 21°20317.513.15.1
Dec29° / 23°2221913.44.2

Cloud cover in August

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 49% of the time in August.

Beyond those clear spells, partly cloudy skies cover about 16% of August, with mostly cloudy or overcast conditions the remaining 35%.

0%25%50%75%100%151015202531
Clearer (%)Cloudier (%)
16535
26535
36436
46436
56436
66436
76436
86436
96436
106436
116436
126535
136535
146535
156535
166634
176634
186535
196535
206634
216634
226634
236634
246634
256634
266535
276535
286535
296535
306535
316535

Chance of precipitation in August

Any precipitation

Rio das Ostras gets around 34 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 24% on the wettest days.

0%10%20%30%151015202531
Rain chance (%)
118
218
318
418
518
618
719
819
919
1020
1120
1220
1320
1421
1521
1621
1722
1822
1922
2022
2122
2222
2322
2422
2522
2622
2722
2823
2923
3023
3124

Humidity in August

DryComfortableHumidMuggyOppressiveMiserable

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

By dew point, August lands in the humid band about 46% of days. Sticky, muggy-or-worse air turns up on roughly 34% of them.

0%25%50%75%100%151015202531
Dry (%)Comfortable (%)Humid (%)Muggy (%)Oppressive (%)
132050280
232050280
331950280
431950290
531949290
631949290
731949290
831849300
931849301
1031848301
1131848301
1231848311
1331847311
1431847311
1531847321
1631847321
1721846321
1821846331
1921746341
2021745341
2121745351
2221645361
2321645371
2421544381
2511544391
2611543401
2711543401
2811542411
2911542411
3021542411
3121542411

Wind in August

Winds average 12 km/h in August.

Across August, daily wind ranges from about 11 km/h on the calmest days to 12 km/h at its breeziest. It stays fairly steady from day to day.

051015151015202531
Wind speed (km/h)Feels
111calm
211calm
311calm
411calm
511calm
611calm
711calm
811calm
911calm
1011calm
1111calm
1212calm
1312calm
1412calm
1512calm
1612calm
1712calm
1812calm
1912calm
2012calm
2112calm
2212calm
2312light breeze
2412light breeze
2512light breeze
2612light breeze
2712light breeze
2812light breeze
2912light breeze
3012light breeze
3112light breeze

Sunrise & sunset in August

DaylightNight

Daylight runs from about 11 hours at the start of August to 11 h 30 min by month's end. The lit band spans sunrise to sunset each day.

Days grow by about 30 minutes over August. Sunrise moves from 7:25 AM to 7:02 AM, and sunset from 6:22 PM to 6:33 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202531
Daylight (h)Sunrise (AM)Sunset (PM)
111.07:256:22
211.07:256:23
311.07:246:23
411.07:246:24
511.07:236:24
611.07:226:24
711.17:226:25
811.17:216:25
911.17:206:26
1011.17:206:26
1111.17:196:26
1211.17:186:27
1311.27:186:27
1411.27:176:28
1511.27:166:28
1611.27:156:28
1711.27:156:29
1811.37:146:29
1911.37:136:29
2011.37:126:30
2111.37:116:30
2211.37:106:31
2311.47:106:31
2411.47:096:31
2511.47:086:32
2611.47:076:32
2711.47:066:32
2811.57:056:33
2911.57:046:33
3011.57:036:33
3111.57:026:33

Solar energy in August

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in August, about 4.38 kWh/m².

For context, solar energy here swings from a low near 3.54 kWh/m² to a high of 6.31 kWh/m² in February across the year — August's 4.38 kWh/m² falls in the middle.

024151015202531
Solar energy (kWh/m²)Level
14.0Moderate
24.0Moderate
34.0Bright
44.0Bright
54.1Bright
64.1Bright
74.1Bright
84.2Bright
94.2Bright
104.2Bright
114.2Bright
124.3Bright
134.3Bright
144.3Bright
154.3Bright
164.3Bright
174.4Bright
184.4Bright
194.4Bright
204.5Bright
214.5Bright
224.5Bright
234.6Bright
244.6Bright
254.6Bright
264.7Bright
274.7Bright
284.7Bright
294.7Bright
304.8Bright
314.8Bright
Planning a trip in August

Hazard calendar for Rio das Ostras

In seasonPeak

None of Rio das Ostras'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 das Ostras's rainy season runs October–March, 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 das Ostras?

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

7.6
Sightseeing
2nd-best month of the year
7.1
Beach & pool
3rd-best month of the year

August is one of the better times to visit Rio das Ostras for general sightseeing. The water and warmth also suit a beach or pool day.

What to pack for Rio das Ostras in August

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

In August, Rio das Ostras sees daytime highs around 26°C and nights near 18°C. Worth packing: light clothes. About 6 days see rain.

light clothes

Sea temperature near Rio das Ostras in August

The nearest coast averages about 22°C in August — the other half of the beach question. The full-year curve and swim-comfort zones are below.

The sea at the nearest coast (about 13 km away) is warmest in March at about 25°C and coldest in September near 21°C.

The water stays above 20°C all year — warm enough for a swim any month.

20°22°24°26°JanFebMarAprMayJunJulAugSepOctNovDeccoolrefreshingwarmcomfortable to swim
Sea temperature (°C)Comfort
Jan24Refreshing
Feb24Warm
Mar25Warm
Apr25Warm
May24Refreshing
Jun23Refreshing
Jul22Refreshing
Aug22Refreshing
Sep21Refreshing
Oct22Refreshing
Nov22Refreshing
Dec24Refreshing

UV index in Rio das Ostras in August

LowModerateHighVery highExtreme

Clear-sky midday UV in August peaks around 8 — 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 das Ostras peaks around January 16 at about 14 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near July 11 at about 6 (high).

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

025710JanFebMarAprMayJunJulAugSepOctNovDecExtremeVery highHighVery highExtremeJan 16UV 14Jul 11UV 6
UV index (midday)Level
Jan14Extreme
Feb14Extreme
Mar13Extreme
Apr9Very high
May7High
Jun6High
Jul6High
Aug8Very high
Sep8Very high
Oct12Extreme
Nov14Extreme
Dec14Extreme
Location & terrain

Where is Rio das Ostras?

Rio das Ostras sits at 22.5°S, 41.9°W, 11 m above sea level, in Brazil. The nearest listed city is Macaé, 23 km away.

Topography around Rio das Ostras

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

Within 3 km, the terrain around Rio das Ostras has only modest variations in elevation — a maximum elevation change of 49 m around an average of 4 m above sea level; within 16 km, large variations in elevation — a maximum elevation change of 693 m; within 80 km, very significant variations in elevation — a maximum elevation change of 2,215 m.

The land around Rio das Ostras is covered by water (39%) and artificial surfaces (32%) within 3 km, water (45%) and grassland (27%) within 16 km, and water (37%), trees (31%) and grassland (28%) within 80 km.

3 km
49 m
16 km
693 m
80 km
2,215 m
treesgrasslandartificial surfacesbare terrainwaterwetlandmangroves
August weather nearby: Macaé 23 km · Buzios 25 km · Casimiro de Abreu 27 km · São Pedro da Aldeia 38 km · Cabo Frio 41 km · Iguaba Grande 45 km · Silva Jardim 48 km · Arraial do Cabo 50 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 das Ostras (-22.5269°, -41.945°, elevation 11 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. Sea temperatures are the NOAA OISST v2.1 1991–2020 monthly climatology (public domain), sampled at the nearest ocean point. UV index is derived from CAMS (Copernicus Atmosphere Monitoring Service) clear-sky UV data — contains modified Copernicus Atmosphere Monitoring Service information. Topography is sampled from the Copernicus DEM GLO-90 elevation model (© ESA/Airbus) and ESA WorldCover 2021 land cover (CC BY 4.0).