São Luís Gonzaga do Maranhão weather in September

In September, São Luís Gonzaga do Maranhão sees average daytime highs of 35°C and overnight lows near 24°C, with 8 mm of rain across 1.4 wet days and about 12 hours of daylight. It is the 2nd-warmest and 11th-wettest month of the year here.

Day-to-day highs hold fairly steady near 35°C through the month. The sky is clear or mostly clear about 69% of the time in September, and the air most often feels oppressive.

Daylight stretches from about 11 h 54 min at the start of September to 12 hours by month's end. Set against the rest of the year, September is São Luís Gonzaga do Maranhão's 2nd-clearest and 2nd-windiest month. For the whole year in context, see São Luís Gonzaga do Maranhão's year-round climate.

Daytime high
35°
2nd warmest
Overnight low
24°
9th coldest
Rainfall
8 mm
1.4 wet days
Daylight
12 hours
5:54 AM – 5:52 PM
Cloud cover
36%
2nd clearest
Wind
8 km/h
2nd windiest
Solar energy
6.27 kWh/m²
Travel score
3.1
out of 10

Temperature in September

Average highAverage lowShaded bands: 10–90% of days

Day-to-day highs hold fairly steady near 35°C through the month.

A typical September day in São Luís Gonzaga do Maranhão reaches about 35°C in the afternoon and slips back to 24°C overnight — a 11°C spread between the day's warmth and the night's chill. On most days the high lands between 34°C and 37°C. Set against its neighbours, September runs about 1°C warmer than August and on par with October.

20°25°30°35°40°151015202530
Avg high (°C)Avg low (°C)
13523
23523
33523
43523
53523
63523
73523
83523
93524
103524
113524
123524
133524
143524
153524
163524
173524
183524
193524
203524
213524
223524
233524
243524
253524
263524
273524
283524
293524
303524

How September really feels in São Luís Gonzaga do Maranhão

Once humidity and wind are folded in, September averages 30 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
30
10 feel dangerously hot (≥ 39°C)
Days feeling ≤ C
0
wind chill below the day's low

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

São Luís Gonzaga do Maranhão weather by month

How September compares with the rest of the year at a glance. September is the 2nd-warmest and 11th-wettest month here — the current month is highlighted below.

MonthHigh / Low (°C)Rainfall (mm)Wet daysDaylight (hours)Travel score
Jan32° / 23°23925.612.22.6
Feb31° / 23°25925.112.12.6
Mar31° / 23°30529122.5
Apr31° / 23°24326.411.92.7
May31° / 23°11817.411.83.6
Jun32° / 23°275.811.84.6
Jul33° / 22°122.411.84.5
Aug34° / 23°5111.93.8
Sep35° / 24°81.4123.1
Oct35° / 25°183.712.12.8
Nov35° / 25°558.712.22.8
Dec33° / 24°13016.312.22.7

Cloud cover in September

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 69% of the time in September.

Beyond those clear spells, partly cloudy skies cover about 20% of September, with mostly cloudy or overcast conditions the remaining 11%. Skies tend to cloud over as the month goes on.

0%25%50%75%100%151015202530
Clearer (%)Cloudier (%)
1919
2919
3919
4919
5919
6919
79010
89010
99010
109010
119010
129010
139010
149010
159010
169010
178911
188911
198911
208911
218911
228911
238812
248911
258812
268812
278812
288713
298713
308713

Chance of precipitation in September

Any precipitation

São Luís Gonzaga do Maranhão gets around 8 mm of rain over 1.4 wet days in September. The line is the day-by-day chance of measurable precipitation.

Day to day, the chance of measurable rain averages around 5% and peaks near 7% on the wettest days.

0%10%20%30%151015202530
Rain chance (%)
14
24
34
44
54
65
75
85
95
104
114
124
134
144
154
164
174
184
194
204
214
225
235
245
255
266
276
286
296
307

Humidity in September

DryComfortableHumidMuggyOppressiveMiserable

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

By dew point, September lands in the oppressive band about 56% of days. Sticky, muggy-or-worse air turns up on roughly 95% of them.

0%25%50%75%100%151015202530
Comfortable (%)Humid (%)Muggy (%)Oppressive (%)
1193852
2083953
3083953
4084052
5084151
6084250
7084249
8084349
9084348
10084348
11074349
12074349
13164350
14164350
15154252
16154153
17144154
18144055
19133957
20133759
21123661
22023563
23023464
24013366
25013366
26013267
27013267
28003268
29003268
30003268

Wind in September

Winds average 8 km/h in September.

Across September, daily wind ranges from about 8 km/h on the calmest days to 8 km/h at its breeziest. It stays fairly steady from day to day.

0246810151015202530
Wind speed (km/h)Feels
18calm
28calm
38calm
48calm
58calm
68calm
78calm
88calm
98calm
108calm
118calm
128calm
138calm
148calm
158calm
168calm
178calm
188calm
198calm
208calm
218calm
228calm
238calm
248calm
258calm
268calm
278calm
288calm
298calm
308calm

Sunrise & sunset in September

DaylightNight

Daylight runs from about 11 h 54 min at the start of September to 12 hours by month's end. The lit band spans sunrise to sunset each day.

Days grow by about 6 minutes over September. Sunrise moves from 6:01 AM to 5:47 AM, and sunset from 5:56 PM to 5:49 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202530
Daylight (h)Sunrise (AM)Sunset (PM)
111.96:015:56
211.96:005:56
311.96:005:55
411.96:005:55
511.95:595:55
611.95:595:55
711.95:585:55
811.95:585:54
911.95:575:54
1012.05:575:54
1112.05:565:54
1212.05:565:53
1312.05:555:53
1412.05:555:53
1512.05:545:53
1612.05:545:52
1712.05:535:52
1812.05:535:52
1912.05:525:52
2012.05:525:51
2112.05:515:51
2212.05:515:51
2312.05:505:51
2412.05:505:50
2512.05:495:50
2612.05:495:50
2712.05:485:50
2812.05:485:49
2912.05:475:49
3012.05:475:49

Solar energy in September

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in September, about 6.27 kWh/m² — the sunniest month for solar.

For context, solar energy here swings from a low near 4.36 kWh/m² to a high of 6.27 kWh/m² in September across the year — September's 6.27 kWh/m² sits near the top of that range.

0246151015202530
Solar energy (kWh/m²)Level
16.1Intense
26.2Intense
36.2Intense
46.2Intense
56.2Intense
66.2Intense
76.2Intense
86.2Intense
96.2Intense
106.2Intense
116.3Intense
126.3Intense
136.3Intense
146.3Intense
156.3Intense
166.3Intense
176.3Intense
186.3Intense
196.3Intense
206.3Intense
216.3Intense
226.3Intense
236.3Intense
246.3Intense
256.3Intense
266.3Intense
276.3Intense
286.3Intense
296.3Intense
306.3Intense
Planning a trip in September

Hazard calendar for São Luís Gonzaga do Maranhão

In seasonPeak

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

São Luís Gonzaga do Maranhão's monsoon runs January–April, when most of the year's rain falls.

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

Is September a good time to visit São Luís Gonzaga do Maranhão?

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

3.1
Sightseeing
5th-best month of the year
6.7
Beach & pool
4th-best month of the year

September is a weaker month for outdoor sightseeing in São Luís Gonzaga do Maranhão. The water and warmth also suit a beach or pool day.

What to pack for São Luís Gonzaga do Maranhão in September

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

In September, São Luís Gonzaga do Maranhão sees daytime highs around 35°C and nights near 24°C. Pack light clothes and sun protection.

light clothessun protection

UV index in São Luís Gonzaga do Maranhão in September

LowModerateHighVery highExtreme

Clear-sky midday UV in September peaks around 12 (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 Gonzaga do Maranhão peaks around March 14 at about 15 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near July 24 at about 10 (very high).

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

025710JanFebMarAprMayJunJulAugSepOctNovDecExtremeVery highExtremeMar 14UV 15Jul 24UV 10
UV index (midday)Level
Jan13Extreme
Feb14Extreme
Mar15Extreme
Apr13Extreme
May11Extreme
Jun10Extreme
Jul10Very high
Aug10Very high
Sep12Extreme
Oct12Extreme
Nov11Extreme
Dec10Extreme

Air quality in São Luís Gonzaga do Maranhão in September

GoodModeratePoorUnhealthyVery unhealthy

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

Air quality in São Luís Gonzaga do Maranhão is worst in November — around 27 µg/m³ PM2.5 (moderate), about 3.2× the cleanest month (June, 9 µg/m³).

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

0102030JanFebMarAprMayJunJulAugSepOctNovDecModerateGoodModerateNov 1426 µg/m³Jun 189 µg/m³
PM2.5 (µg/m³)Level
Jan15Moderate
Feb15Moderate
Mar14Moderate
Apr13Moderate
May11Good
Jun9Good
Jul10Good
Aug10Good
Sep13Moderate
Oct22Moderate
Nov27Moderate
Dec20Moderate
Location & terrain

Where is São Luís Gonzaga do Maranhão?

São Luís Gonzaga do Maranhão sits at 4.4°S, 44.7°W, 38 m above sea level, in Brazil. The nearest listed city is Bacabal, 20 km away.

Topography around São Luís Gonzaga do Maranhão

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

Within 3 km, the terrain around São Luís Gonzaga do Maranhão has only modest variations in elevation — a maximum elevation change of 54 m around an average of 30 m above sea level; within 16 km, only modest variations in elevation — a maximum elevation change of 134 m; within 80 km, significant variations in elevation — a maximum elevation change of 275 m.

The land around São Luís Gonzaga do Maranhão is covered by grassland (64%) and trees (27%) within 3 km, grassland (60%) and trees (37%) within 16 km, and grassland (53%) and trees (42%) within 80 km.

3 km
54 m
16 km
134 m
80 km
275 m
treesshrubsgrasslandartificial surfaceswaterwetland
September weather nearby: Bacabal 20 km · Trizidela do Vale 22 km · Pedreiras 23 km · Alto Alegre do Maranhão 31 km · Peritoró 37 km · São Mateus do Maranhão 43 km · Poção de Pedras 51 km · Lago da Pedra 55 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 Gonzaga do Maranhão (-4.3788°, -44.6711°, elevation 38 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).