São Sebastião do Caí weather in August

In August, São Sebastião do Caí sees average daytime highs of 21°C and overnight lows near 11°C, with 145 mm of rain across 10.7 wet days and about 10.9 hours of daylight. It is the 9th-warmest and 9th-wettest month of the year here.

Highs climb over the month, from about 20°C in the first days to 22°C by the end. The sky is clear or mostly clear about 38% of the time in August, and the air most often feels dry.

Daylight stretches from about 10 h 36 min at the start of August to 11 h 18 min by month's end. Set against the rest of the year, August is São Sebastião do Caí's 1st-clearest and 2nd-windiest month. For the whole year in context, see São Sebastião do Caí's year-round climate.

Daytime high
21°
9th warmest
Overnight low
11°
3rd coldest
Rainfall
145 mm
10.7 wet days
Daylight
10 h 54 min
8:02 AM – 6:57 PM
Cloud cover
54%
1st clearest
Wind
9 km/h
2nd windiest
Solar energy
3.41 kWh/m²
Travel score
6.4
out of 10

Temperature in August

Average highAverage lowShaded bands: 10–90% of days

Highs climb over the month, from about 20°C in the first days to 22°C by the end.

A typical August day in São Sebastião do Caí reaches about 21°C in the afternoon and slips back to 11°C overnight — a 10°C spread between the day's warmth and the night's chill. On most days the high lands between 13°C and 28°C. Set against its neighbours, August runs about 2°C warmer than July and about 1°C cooler than September.

10°20°30°151015202531
Avg high (°C)Avg low (°C)
1199
21910
32010
42010
52010
62010
72010
82010
92010
102010
112010
122010
132010
142110
152110
162111
172111
182111
192111
202111
212111
222111
232111
242111
252211
262211
272211
282211
292211
302211
312211

São Sebastião do Caí weather by month

How August compares with the rest of the year at a glance. August is the 9th-warmest and 9th-wettest month here — the current month is highlighted below.

MonthHigh / Low (°C)Rainfall (mm)Wet daysDaylight (hours)Travel score
Jan29° / 19°20917.613.74.7
Feb28° / 19°18016.613.14.8
Mar27° / 18°15415.212.25.8
Apr24° / 15°14211.211.36.6
May21° / 12°13610.410.56.4
Jun19° / 10°14410.310.16.0
Jul19° / 18010.810.36.0
Aug21° / 11°14510.710.96.4
Sep22° / 12°17812.511.86.1
Oct24° / 14°21614.812.76.0
Nov26° / 16°16412.813.56.2
Dec28° / 18°18215.113.95.4

Cloud cover in August

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 38% of the time in August, the clearest month of the year.

Beyond those clear spells, partly cloudy skies cover about 12% of August, with mostly cloudy or overcast conditions the remaining 50%.

0%25%50%75%100%151015202531
Clearer (%)Cloudier (%)
14852
24852
34753
44753
54753
64753
74753
84852
94753
104753
114753
124852
134852
144852
154951
165050
175050
185248
195248
205248
215347
225347
235347
245347
255347
265248
275248
285149
295149
305050
315050

Chance of precipitation in August

Any precipitation

São Sebastião do Caí gets around 145 mm of rain over 10.7 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 35% and peaks near 35% on the wettest days.

0%10%20%30%40%50%151015202531
Rain chance (%)
134
235
335
435
535
635
735
835
935
1035
1135
1235
1335
1435
1534
1634
1734
1834
1934
2034
2134
2234
2334
2434
2534
2635
2735
2835
2935
3035
3135

Humidity in August

DryComfortableHumidMuggyOppressiveMiserable

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

By dew point, August lands in the dry band about 59% of days. It rarely turns muggy — the humid and sticky bands barely register.

0%25%50%75%100%151015202531
Dry (%)Comfortable (%)Humid (%)Muggy (%)
1672760
2672760
3662770
4662770
5662770
6662770
7652870
8652870
9652870
10642970
11642970
12623080
13623080
14623080
15613180
16603190
17593290
185832100
195832100
205732110
215732110
225632120
235432131
245332141
255332141
265331151
275331151
285330161
295330161
305130172
315229172

Wind in August

Winds average 9 km/h in August.

Across August, daily wind ranges from about 9 km/h on the calmest days to 9 km/h at its breeziest. It stays fairly steady from day to day.

051015151015202531
Wind speed (km/h)Feels
19calm
29calm
39calm
49calm
59calm
69calm
79calm
89calm
99calm
109calm
119calm
129calm
139calm
149calm
159calm
169calm
179calm
189calm
199calm
209calm
219calm
229calm
239calm
249calm
259calm
269calm
279calm
289calm
299calm
309calm
319calm

Sunrise & sunset in August

DaylightNight

Daylight runs from about 10 h 36 min at the start of August to 11 h 18 min by month's end. The lit band spans sunrise to sunset each day.

Days grow by about 42 minutes over August. Sunrise moves from 8:15 AM to 7:45 AM, and sunset from 6:48 PM to 7:06 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202531
Daylight (h)Sunrise (AM)Sunset (PM)
110.68:156:48
210.68:146:49
310.68:136:50
410.68:126:50
510.78:126:51
610.78:116:51
710.78:106:52
810.78:096:53
910.78:086:53
1010.88:076:54
1110.88:076:54
1210.88:066:55
1310.88:056:56
1410.98:046:56
1510.98:036:57
1610.98:026:57
1711.08:016:58
1811.08:006:59
1911.07:596:59
2011.07:587:00
2111.17:577:00
2211.17:567:01
2311.17:547:01
2411.17:537:02
2511.27:527:03
2611.27:517:03
2711.27:507:04
2811.37:497:04
2911.37:487:05
3011.37:467:05
3111.37:457:06

Solar energy in August

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in August, about 3.41 kWh/m².

For context, solar energy here swings from a low near 2.41 kWh/m² to a high of 6.44 kWh/m² in December across the year — August's 3.41 kWh/m² falls in the middle.

01234151015202531
Solar energy (kWh/m²)Level
13.0Moderate
23.0Moderate
33.0Moderate
43.0Moderate
53.1Moderate
63.1Moderate
73.1Moderate
83.1Moderate
93.2Moderate
103.2Moderate
113.2Moderate
123.3Moderate
133.3Moderate
143.3Moderate
153.4Moderate
163.4Moderate
173.4Moderate
183.5Moderate
193.5Moderate
203.5Moderate
213.6Moderate
223.6Moderate
233.6Moderate
243.7Moderate
253.7Moderate
263.7Moderate
273.7Moderate
283.8Moderate
293.8Moderate
303.8Moderate
313.8Moderate
Planning a trip in August

Is August a good time to visit São Sebastião do Caí?

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

6.4
Sightseeing
2nd-best month of the year
3.7
Beach & pool
10th-best month of the year

August is a reasonable time to visit São Sebastião do Caí for sightseeing.

What to pack for São Sebastião do Caí in August

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

In August, São Sebastião do Caí sees daytime highs around 21°C and nights near 11°C. Worth packing: rain gear. About 11 days see rain.

rain gear

UV index in São Sebastião do Caí in August

LowModerateHighVery highExtreme

Clear-sky midday UV in August peaks around 5 — 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 do Caí peaks around January 16 at about 13 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near June 20 at about 4 (moderate).

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

025710JanFebMarAprMayJunJulAugSepOctNovDecExtremeVery highModerateHighVery highExtremeJan 16UV 13Jun 20UV 4
UV index (midday)Level
Jan13Extreme
Feb12Extreme
Mar10Very high
Apr8Very high
May5Moderate
Jun4Moderate
Jul4Moderate
Aug5High
Sep8Very high
Oct8Very high
Nov12Extreme
Dec13Extreme

Air quality in São Sebastião do Caí 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 do Caí is worst in September — around 17 µg/m³ PM2.5 (moderate), about 1.8× the cleanest month (December, 10 µg/m³).

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

01020JanFebMarAprMayJunJulAugSepOctNovDecGoodModerateGoodSep 1217 µg/m³Dec 1910 µg/m³
PM2.5 (µg/m³)Level
Jan10Good
Feb10Good
Mar10Good
Apr12Good
May12Good
Jun11Good
Jul13Moderate
Aug16Moderate
Sep17Moderate
Oct12Good
Nov11Good
Dec10Good
Location & terrain

Where is São Sebastião do Caí?

São Sebastião do Caí sits at 29.6°S, 51.4°W, 16 m above sea level, in Brazil. The nearest listed city is Montenegro, 14 km away.

Topography around São Sebastião do Caí

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

Within 3 km, the terrain around São Sebastião do Caí has only modest variations in elevation — a maximum elevation change of 107 m around an average of 32 m above sea level; within 16 km, significant variations in elevation — a maximum elevation change of 512 m; within 80 km, large variations in elevation — a maximum elevation change of 988 m.

The land around São Sebastião do Caí is covered by trees (69%) within 3 km, trees (73%) within 16 km, and trees (62%) within 80 km.

3 km
107 m
16 km
512 m
80 km
988 m
treesgrasslandcroplandartificial surfaceswaterwetland
August weather nearby: Montenegro 14 km · Portão 18 km · Estância Velha 21 km · Ivoti 21 km · Novo Hamburgo 26 km · Dois Irmãos 28 km · São Leopoldo 29 km · Nova Santa Rita 31 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 do Caí (-29.5867°, -51.3756°, elevation 16 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).