São Luís weather in August

In August, São Luís sees average daytime highs of 29°C and overnight lows near 26°C, with 28 mm of rain across 9 wet days and about 11.9 hours of daylight. It is the 1st-warmest and 9th-wettest month of the year here.

Day-to-day highs hold fairly steady near 29°C through the month. The sky is clear or mostly clear about 75% of the time in August, and the air most often feels oppressive.

Daylight stretches from about 11 h 54 min at the start of August to 11 h 54 min by month's end. Set against the rest of the year, August is São Luís's 2nd-clearest and 5th-windiest month. For the whole year in context, see São Luís's year-round climate.

Daytime high
29°
1st warmest
Overnight low
26°
9th coldest
Rainfall
28 mm
9 wet days
Daylight
11 h 54 min
6:04 AM – 5:59 PM
Cloud cover
33%
2nd clearest
Wind
19 km/h
5th windiest
Solar energy
5.82 kWh/m²
Travel score
6.1
out of 10

São Luís 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 29°C through the month.

A typical August day in São Luís reaches about 29°C in the afternoon and slips back to 26°C overnight — a 3°C spread between the day's warmth and the night's chill. On most days the high lands between 28°C and 30°C. Set against its neighbours, August runs on par with July and on par with September.

25°28°30°33°35°151015202531
Avg high (°C)Avg low (°C)
12926
22926
32926
42926
52926
62926
72926
82926
92926
102926
112926
122926
132926
142926
152926
162926
172926
182926
192926
202926
212926
222926
232926
242926
252926
262926
272926
282926
292926
302926
312926

How August really feels in São Luís

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.

São Luís weather by month

How August compares with the rest of the year at a glance. August is the 1st-warmest and 9th-wettest month here — the current month is highlighted below.

MonthHigh / Low (°C)Rainfall (mm)Wet daysDaylight (hours)Travel score
Jan28° / 25°22125.412.14.0
Feb28° / 25°3032612.13.6
Mar27° / 25°44030.3123.4
Apr28° / 25°41428.811.93.4
May28° / 26°28626.911.93.7
Jun28° / 26°1532311.94.2
Jul29° / 26°1032011.94.7
Aug29° / 26°28911.96.1
Sep29° / 26°113.2127.0
Oct28° / 26°133.612.16.9
Nov29° / 26°276.812.16.3
Dec28° / 26°7315.312.15.2

Cloud cover in August

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 75% of the time in August.

Beyond those clear spells, partly cloudy skies cover about 17% of August, with mostly cloudy or overcast conditions the remaining 8%. Skies tend to open up as the month goes on.

0%25%50%75%100%151015202531
Clearer (%)Cloudier (%)
1919
2919
3928
4919
5919
6919
7919
8919
9919
109010
119010
129010
139010
149010
159010
169010
179010
189010
19919
20919
21919
22928
23928
24937
25937
26937
27946
28946
29955
30964
31964

Chance of precipitation in August

Any precipitation

São Luís gets around 28 mm of rain over 9 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 29% and peaks near 44% on the wettest days. The odds ease toward the end of the month.

0%10%20%30%40%50%151015202531
Rain chance (%)
144
243
341
440
539
637
736
835
934
1033
1132
1231
1330
1430
1529
1628
1727
1827
1926
2025
2125
2224
2323
2422
2521
2620
2720
2819
2918
3017
3117

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 99% of days. Sticky, muggy-or-worse air turns up on roughly 100% of them.

0%25%50%75%100%151015202531
Muggy (%)Oppressive (%)Miserable (%)
10991
201000
301000
401000
501000
60991
70991
80991
90991
100991
110991
121981
131981
141981
151981
161981
171981
181981
191981
201981
211981
221981
230991
240991
250991
260991
270991
280991
290991
300991
310991

Wind in August

Winds average 19 km/h in August.

Across August, daily wind ranges from about 17 km/h on the calmest days to 21 km/h at its breeziest. It stays fairly steady from day to day.

0510152025151015202531
Wind speed (km/h)Feels
117light breeze
217light breeze
317light breeze
417light breeze
517light breeze
617light breeze
718light breeze
818light breeze
918light breeze
1018light breeze
1118light breeze
1218light breeze
1318light breeze
1419light breeze
1519light breeze
1619light breeze
1719light breeze
1819light breeze
1919light breeze
2019light breeze
2120light breeze
2220light breeze
2320light breeze
2420breezy
2520breezy
2620breezy
2721breezy
2821breezy
2921breezy
3021breezy
3121breezy

Sunrise & sunset in August

DaylightNight

Daylight runs from about 11 h 54 min at the start of August to 11 h 54 min by month's end. The lit band spans sunrise to sunset each day.

Days grow by about 0 minutes over August. Sunrise moves from 6:07 AM to 5:59 AM, and sunset from 6:00 PM to 5:56 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202531
Daylight (h)Sunrise (AM)Sunset (PM)
111.96:076:00
211.96:066:00
311.96:066:00
411.96:066:00
511.96:066:00
611.96:066:00
711.96:066:00
811.96:066:00
911.96:056:00
1011.96:056:00
1111.96:055:59
1211.96:055:59
1311.96:055:59
1411.96:045:59
1511.96:045:59
1611.96:045:59
1711.96:045:59
1811.96:035:58
1911.96:035:58
2011.96:035:58
2111.96:025:58
2211.96:025:58
2311.96:025:58
2411.96:015:57
2511.96:015:57
2611.96:015:57
2711.96:005:57
2811.96:005:56
2911.96:005:56
3011.95:595:56
3111.95:595:56

Solar energy in August

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in August, about 5.82 kWh/m².

For context, solar energy here swings from a low near 4.57 kWh/m² to a high of 6.4 kWh/m² in October across the year — August's 5.82 kWh/m² falls in the middle.

0246151015202531
Solar energy (kWh/m²)Level
15.5Bright
25.6Bright
35.6Bright
45.6Bright
55.6Bright
65.6Bright
75.7Bright
85.7Bright
95.7Bright
105.7Bright
115.7Bright
125.8Bright
135.8Bright
145.8Bright
155.8Bright
165.8Bright
175.8Bright
185.9Bright
195.9Bright
205.9Bright
215.9Bright
225.9Bright
235.9Bright
246.0Bright
256.0Bright
266.0Bright
276.0Intense
286.0Intense
296.0Intense
306.1Intense
316.1Intense
Planning a trip in August

Hazard calendar for São Luís

In seasonPeak

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

São Luís's monsoon runs January–May, when most of the year's rain falls.

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

Is August a good time to visit São Luís?

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

6.1
Sightseeing
4th-best month of the year
7.7
Beach & pool
3rd-best month of the year

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

What to pack for São Luís in August

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

In August, São Luís sees daytime highs around 29°C and nights near 26°C. Pack light clothes. Worth having: rain gear and sun protection. About 9 days see rain.

light clothesrain gearsun protection

Sea temperature near São Luís in August

The nearest coast averages about 28°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 May at about 29°C and coldest in October near 28°C.

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

26°28°30°JanFebMarAprMayJunJulAugSepOctNovDecwarmtropicalcomfortable to swim
Sea temperature (°C)Comfort
Jan28Tropical
Feb28Tropical
Mar28Tropical
Apr29Tropical
May29Tropical
Jun29Tropical
Jul28Tropical
Aug28Tropical
Sep28Warm
Oct28Warm
Nov28Warm
Dec28Warm

UV index in São Luís in August

LowModerateHighVery highExtreme

Clear-sky midday UV in August peaks around 10 (very high — sun protection essential). The full-year curve, shaded by WHO exposure level, is below.

Under clear skies, the midday UV index in São Luís peaks around March 17 at about 15 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near July 17 at about 10 (extreme).

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

025710JanFebMarAprMayJunJulAugSepOctNovDecExtremeMar 17UV 15Jul 17UV 10
UV index (midday)Level
Jan13Extreme
Feb14Extreme
Mar16Extreme
Apr14Extreme
May12Extreme
Jun10Extreme
Jul10Very high
Aug10Extreme
Sep12Extreme
Oct12Extreme
Nov11Extreme
Dec11Extreme

Air quality in São Luís 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 Luís is worst in February — around 18 µg/m³ PM2.5 (moderate), about 2.7× the cleanest month (July, 7 µg/m³).

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

0102030JanFebMarAprMayJunJulAugSepOctNovDecModerateGoodFeb 2018 µg/m³Jul 157 µg/m³
PM2.5 (µg/m³)Level
Jan14Moderate
Feb18Moderate
Mar18Moderate
Apr13Moderate
May8Good
Jun7Good
Jul7Good
Aug8Good
Sep9Good
Oct10Good
Nov10Good
Dec11Good
Location & terrain

Where is São Luís?

São Luís sits at 2.5°S, 44.3°W, 29 m above sea level, in Brazil. The nearest listed city is Alcântara, 19 km away.

Topography around São Luís

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

Within 3 km, the terrain around São Luís has only modest variations in elevation — a maximum elevation change of 37 m around an average of 8 m above sea level; within 16 km, only modest variations in elevation — a maximum elevation change of 65 m; within 80 km, only modest variations in elevation — a maximum elevation change of 102 m.

The land around São Luís is covered by artificial surfaces (38%) and water (33%) within 3 km, water (52%) and trees (20%) within 16 km, and water (36%) and trees (35%) within 80 km.

3 km
37 m
16 km
65 m
80 km
102 m
treesshrubsgrasslandartificial surfacesbare terrainwaterwetlandmangroves
August weather nearby: Alcântara 19 km · Paço do Lumiar 22 km · Raposa 25 km · São José de Ribamar 27 km · Icatu 38 km · Rosário 46 km · Morros 47 km · Bacabeira 49 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 Luís (-2.5297°, -44.3028°, elevation 29 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).