São Sebastião weather in August

In August, São Sebastião sees average daytime highs of 22°C and overnight lows near 18°C, with 75 mm of rain across 8.9 wet days and about 11.2 hours of daylight. It is the 12th-warmest and 12th-wettest month of the year here.

Day-to-day highs hold fairly steady near 22°C through the month. The sky is clear or mostly clear about 45% of the time in August, and the air most often feels humid.

Daylight stretches from about 10 h 54 min at the start of August to 11 h 30 min by month's end. Set against the rest of the year, August is São Sebastião's 2nd-clearest and 4th-windiest month. For the whole year in context, see São Sebastião's year-round climate.

Daytime high
22°
12th warmest
Overnight low
18°
2nd coldest
Rainfall
75 mm
8.9 wet days
Daylight
11 h 12 min
7:31 AM – 6:41 PM
Cloud cover
49%
2nd clearest
Wind
10 km/h
4th windiest
Solar energy
4.1 kWh/m²
Travel score
7.0
out of 10

São Sebastião is 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 22°C through the month.

A typical August day in São Sebastião reaches about 22°C in the afternoon and slips back to 18°C overnight — a 4°C spread between the day's warmth and the night's chill. On most days the high lands between 18°C and 26°C. Set against its neighbours, August runs on par with July and on par with September.

15°20°25°30°151015202531
Avg high (°C)Avg low (°C)
12217
22217
32217
42217
52217
62217
72218
82218
92218
102218
112218
122218
132218
142218
152218
162218
172218
182218
192218
202218
212218
222218
232218
242218
252218
262218
272218
282218
292218
302218
312218

São Sebastião weather by month

How August compares with the rest of the year at a glance. August is the 12th-warmest and 12th-wettest month here — the current month is highlighted below.

MonthHigh / Low (°C)Rainfall (mm)Wet daysDaylight (hours)Travel score
Jan27° / 24°27722.413.34.6
Feb27° / 24°22819.612.84.7
Mar27° / 23°23620.612.25.0
Apr25° / 22°13013.711.56.2
May23° / 20°11512.110.96.6
Jun23° / 18°829.510.67.0
Jul22° / 18°928.810.77.0
Aug22° / 18°758.911.27.0
Sep22° / 19°13213.711.96.1
Oct23° / 20°14715.212.65.8
Nov24° / 21°18717.513.15.6
Dec26° / 22°21419.213.45.1

Cloud cover in August

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 45% of the time in August.

Beyond those clear spells, partly cloudy skies cover about 11% of August, with mostly cloudy or overcast conditions the remaining 44%.

0%25%50%75%100%151015202531
Clearer (%)Cloudier (%)
15644
25644
35644
45644
55644
65545
75644
85644
95644
105545
115644
125644
135644
145644
155644
165644
175743
185743
195743
205743
215743
225743
235743
245743
255743
265743
275644
285644
295644
305644
315446

Chance of precipitation in August

Any precipitation

São Sebastião gets around 75 mm of rain over 8.9 wet days in August, the driest month. The line is the day-by-day chance of measurable precipitation.

Day to day, the chance of measurable rain averages around 29% and peaks near 34% on the wettest days.

0%10%20%30%40%151015202531
Rain chance (%)
130
230
330
429
529
629
729
829
929
1029
1128
1228
1328
1428
1528
1627
1727
1827
1927
2028
2128
2228
2329
2429
2530
2630
2731
2832
2932
3033
3134

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 54% of days. Sticky, muggy-or-worse air turns up on roughly 22% of them.

0%25%50%75%100%151015202531
Dry (%)Comfortable (%)Humid (%)Muggy (%)
18176312
28176213
38176213
48176114
58176114
68176015
78185816
88185717
98185618
108185519
118185420
128185321
138185321
148185222
158185123
168175223
178175124
188175124
198175124
207165225
217165225
227155226
236155326
246155227
256155227
265155228
275155129
285155129
295155030
304155031
314155032

Wind in August

Winds average 10 km/h in August.

Across August, daily wind ranges from about 10 km/h on the calmest days to 10 km/h at its breeziest. It stays fairly steady from day to day.

051015151015202531
Wind speed (km/h)Feels
110calm
210calm
310calm
410calm
510calm
610calm
710calm
810calm
910calm
1010calm
1110calm
1210calm
1310calm
1410calm
1510calm
1610calm
1710calm
1810calm
1910calm
2010calm
2110calm
2210calm
2310calm
2410calm
2510calm
2610calm
2710calm
2810calm
2910calm
3010calm
3110calm

Sunrise & sunset in August

DaylightNight

Daylight runs from about 10 h 54 min 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 36 minutes over August. Sunrise moves from 7:41 AM to 7:17 AM, and sunset from 6:34 PM to 6:46 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202531
Daylight (h)Sunrise (AM)Sunset (PM)
110.97:416:34
210.97:406:35
310.97:406:35
410.97:396:36
511.07:396:36
611.07:386:37
711.07:376:37
811.07:376:37
911.07:366:38
1011.17:356:38
1111.17:356:39
1211.17:346:39
1311.17:336:40
1411.17:326:40
1511.17:316:40
1611.27:316:41
1711.27:306:41
1811.27:296:42
1911.27:286:42
2011.37:276:42
2111.37:266:43
2211.37:266:43
2311.37:256:44
2411.37:246:44
2511.47:236:44
2611.47:226:45
2711.47:216:45
2811.47:206:45
2911.47:196:46
3011.57:186:46
3111.57:176:46

Solar energy in August

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in August, about 4.1 kWh/m².

For context, solar energy here swings from a low near 3.22 kWh/m² to a high of 5.9 kWh/m² in December across the year — August's 4.1 kWh/m² falls in the middle.

012345151015202531
Solar energy (kWh/m²)Level
13.6Moderate
23.7Moderate
33.7Moderate
43.7Moderate
53.8Moderate
63.8Moderate
73.8Moderate
83.8Moderate
93.9Moderate
103.9Moderate
113.9Moderate
124.0Moderate
134.0Bright
144.0Bright
154.1Bright
164.1Bright
174.1Bright
184.2Bright
194.2Bright
204.2Bright
214.3Bright
224.3Bright
234.3Bright
244.3Bright
254.4Bright
264.4Bright
274.4Bright
284.4Bright
294.5Bright
304.5Bright
314.5Bright
Planning a trip in August

Is August a good time to visit São Sebastião?

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

7.0
Sightseeing
1st-best month of the year
4.7
Beach & pool
9th-best month of the year

August is one of the better times to visit São Sebastião for general sightseeing.

What to pack for São Sebastião in August

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

In August, São Sebastião sees daytime highs around 22°C and nights near 18°C. Worth packing: rain gear. About 9 days see rain.

rain gear

Sea temperature near São Sebastião in August

The nearest coast averages about 21°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 25 km away) is warmest in February at about 27°C and coldest in August near 21°C.

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

20°25°JanFebMarAprMayJunJulAugSepOctNovDeccoolrefreshingwarmtropicalcomfortable to swim
Sea temperature (°C)Comfort
Jan26Warm
Feb27Warm
Mar27Warm
Apr26Warm
May24Refreshing
Jun22Refreshing
Jul21Refreshing
Aug21Refreshing
Sep21Refreshing
Oct22Refreshing
Nov23Refreshing
Dec25Warm

UV index in São Sebastião 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 São Sebastião peaks around February 8 at about 14 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near July 11 at about 5 (high).

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

025710JanFebMarAprMayJunJulAugSepOctNovDecExtremeVery highHighVery highExtremeFeb 8UV 14Jul 11UV 5
UV index (midday)Level
Jan14Extreme
Feb14Extreme
Mar11Extreme
Apr9Very high
May7High
Jun6High
Jul5High
Aug8Very high
Sep8Very high
Oct11Extreme
Nov13Extreme
Dec14Extreme

Air quality in São Sebastião 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 São Sebastião is worst in June — around 23 µg/m³ PM2.5 (moderate), about 1.8× the cleanest month (November, 13 µg/m³).

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

0102030JanFebMarAprMayJunJulAugSepOctNovDecModerateJun 2223 µg/m³Nov 2313 µg/m³
PM2.5 (µg/m³)Level
Jan13Moderate
Feb13Moderate
Mar13Moderate
Apr14Moderate
May18Moderate
Jun23Moderate
Jul23Moderate
Aug22Moderate
Sep21Moderate
Oct16Moderate
Nov13Moderate
Dec13Moderate
Location & terrain

Where is São Sebastião?

São Sebastião sits at 23.8°S, 45.4°W, 6 m above sea level, in Brazil. The nearest listed city is Ilhabela, 6.0 km away.

Topography around São Sebastião

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

Within 3 km, the terrain around São Sebastião has large variations in elevation — a maximum elevation change of 806 m around an average of 181 m above sea level; within 16 km, very significant variations in elevation — a maximum elevation change of 1,359 m; within 80 km, very significant variations in elevation — a maximum elevation change of 1,647 m.

The land around São Sebastião is covered by trees (50%) and water (39%) within 3 km, trees (53%) and water (36%) within 16 km, and water (53%) and trees (33%) within 80 km.

3 km
806 m
16 km
1,359 m
80 km
1,647 m
treesgrasslandartificial surfaceswater
August weather nearby: Ilhabela 6.0 km · Caraguatatuba 16 km · Paraibuna 49 km · Ubatuba 50 km · Salesópolis 52 km · Biritiba Mirim 67 km · Guararema 74 km · Bertioga 75 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 São Sebastião (-23.76°, -45.4097°, elevation 6 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. 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).