Alcântara weather in September

In September, Alcântara sees average daytime highs of 31°C and overnight lows near 26°C, with 11 mm of rain across 2.2 wet days and about 12 hours of daylight. It is the 1st-warmest and 12th-wettest month of the year here.

Day-to-day highs hold fairly steady near 31°C through the month. The sky is clear or mostly clear about 75% of the time in September, and the air most often feels oppressive.

Daylight stretches from about 12 hours at the start of September to 12 hours by month's end. Set against the rest of the year, September is Alcântara's 1st-clearest and 2nd-windiest month. For the whole year in context, see Alcântara's year-round climate.

Daytime high
31°
1st warmest
Overnight low
26°
10th coldest
Rainfall
11 mm
2.2 wet days
Daylight
12 hours
5:52 AM – 5:52 PM
Cloud cover
34%
1st clearest
Wind
17 km/h
2nd windiest
Solar energy
6.16 kWh/m²
Travel score
5.8
out of 10

Alcântara is town in Maranhao, Brazil.

Air quality: WHO Ambient Air Quality Database. Density & description: Wikidata (CC0), GeoNames.

Temperature in September

Average highAverage lowShaded bands: 10–90% of days

Day-to-day highs hold fairly steady near 31°C through the month.

A typical September day in Alcântara reaches about 31°C in the afternoon and slips back to 26°C overnight — a 5°C spread between the day's warmth and the night's chill. On most days the high lands between 30°C and 31°C. Set against its neighbours, September runs on par with August and on par with October.

20°25°30°35°151015202530
Avg high (°C)Avg low (°C)
13125
23125
33125
43126
53126
63126
73126
83126
93126
103126
113126
123126
133126
143126
153126
163126
173126
183126
193126
203126
213126
223126
233126
243126
253126
263126
273126
283126
293126
303126

How September really feels in Alcântara

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
heat index over the day's high
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.

Alcântara weather by month

How September compares with the rest of the year at a glance. September is the 1st-warmest and 12th-wettest month here — the current month is highlighted below.

MonthHigh / Low (°C)Rainfall (mm)Wet daysDaylight (hours)Travel score
Jan30° / 25°18824.212.13.4
Feb29° / 25°26025.812.13.1
Mar29° / 24°39130.3122.9
Apr29° / 25°37628.711.93.0
May29° / 25°26526.511.93.3
Jun29° / 25°12920.811.94.0
Jul30° / 25°8317.111.94.7
Aug30° / 25°236.811.95.5
Sep31° / 26°112.2125.8
Oct31° / 26°122.712.15.7
Nov31° / 26°214.912.15.3
Dec30° / 26°5812.612.14.5

Cloud cover in September

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 75% of the time in September, the clearest month of the year.

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

0%25%50%75%100%151015202530
Clearer (%)Cloudier (%)
1937
2937
3937
4937
5937
6946
7946
8946
9946
10946
11946
12937
13928
14928
15928
16928
17928
18928
19919
20919
21919
22919
23919
24919
25919
26919
27919
28919
299010
309010

Chance of precipitation in September

Any precipitation

Alcântara gets around 11 mm of rain over 2.2 wet days in September, the driest month. The line is the day-by-day chance of measurable precipitation.

Day to day, the chance of measurable rain averages around 8% and peaks near 10% on the wettest days.

0%10%20%30%151015202530
Rain chance (%)
110
210
310
49
59
68
78
88
98
108
118
128
138
148
158
168
178
188
198
208
218
228
238
248
258
268
278
288
298
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 100% of days. Sticky, muggy-or-worse air turns up on roughly 100% of them.

0%25%50%75%100%151015202530
Oppressive (%)Miserable (%)
1991
21000
31000
41000
51000
61000
71000
81000
91000
101000
111000
121000
131000
141000
151000
161000
171000
181000
191000
201000
211000
221000
231000
241000
251000
261000
271000
281000
291000
301000

Wind in September

Winds average 17 km/h in September.

Across September, daily wind ranges from about 16 km/h on the calmest days to 17 km/h at its breeziest. It stays fairly steady from day to day.

05101520151015202530
Wind speed (km/h)Feels
116light breeze
216light breeze
316light breeze
416light breeze
516light breeze
616light breeze
716light breeze
816light breeze
916light breeze
1016light breeze
1116light breeze
1217light breeze
1317light breeze
1417light breeze
1517light breeze
1617light breeze
1717light breeze
1817light breeze
1917light breeze
2017light breeze
2117light breeze
2217light breeze
2317light breeze
2417light breeze
2517light breeze
2617light breeze
2717light breeze
2817light breeze
2917light breeze
3017light breeze

Sunrise & sunset in September

DaylightNight

Daylight runs from about 12 hours 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 0 minutes over September. Sunrise moves from 5:59 AM to 5:46 AM, and sunset from 5:56 PM to 5:48 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202530
Daylight (h)Sunrise (AM)Sunset (PM)
112.05:595:56
212.05:585:56
312.05:585:55
412.05:585:55
512.05:575:55
612.05:575:55
712.05:565:54
812.05:565:54
912.05:555:54
1012.05:555:53
1112.05:555:53
1212.05:545:53
1312.05:545:53
1412.05:535:52
1512.05:535:52
1612.05:525:52
1712.05:525:51
1812.05:515:51
1912.05:515:51
2012.05:515:50
2112.05:505:50
2212.05:505:50
2312.05:495:49
2412.05:495:49
2512.05:485:49
2612.05:485:49
2712.05:485:48
2812.05:475:48
2912.05:475:48
3012.05:465:48

Solar energy in September

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in September, about 6.16 kWh/m².

For context, solar energy here swings from a low near 4.43 kWh/m² to a high of 6.31 kWh/m² in October across the year — September's 6.16 kWh/m² sits near the top of that range.

0246151015202530
Solar energy (kWh/m²)Level
16.0Bright
26.0Bright
36.0Intense
46.0Intense
56.0Intense
66.0Intense
76.1Intense
86.1Intense
96.1Intense
106.1Intense
116.1Intense
126.1Intense
136.1Intense
146.2Intense
156.2Intense
166.2Intense
176.2Intense
186.2Intense
196.2Intense
206.2Intense
216.2Intense
226.2Intense
236.2Intense
246.2Intense
256.2Intense
266.3Intense
276.3Intense
286.3Intense
296.3Intense
306.3Intense
Planning a trip in September

Hazard calendar for Alcântara

In seasonPeak

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

Alcântara'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 September a good time to visit Alcântara?

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

5.8
Sightseeing
1st-best month of the year
8.3
Beach & pool
1st-best month of the year

September is a reasonable time to visit Alcântara for sightseeing. The water and warmth also suit a beach or pool day.

What to pack for Alcântara in September

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

In September, Alcântara sees daytime highs around 31°C and nights near 26°C. Pack light clothes and sun protection.

light clothessun protection

Sea temperature near Alcântara in September

The nearest coast averages about 28°C in September — the other half of the beach question. The full-year curve and swim-comfort zones are below.

The sea offshore 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
Dec28Tropical

UV index in Alcântara 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 Alcântara 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 Alcântara 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 Alcântara 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 Alcântara?

Alcântara sits at 2.4°S, 44.4°W, 32 m above sea level, in Brazil. The nearest listed city is São Luís, 19 km away.

Topography around Alcântara

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

Within 3 km, the terrain around Alcântara has only modest variations in elevation — a maximum elevation change of 58 m around an average of 12 m above sea level; within 16 km, only modest variations in elevation — a maximum elevation change of 64 m; within 80 km, only modest variations in elevation — a maximum elevation change of 102 m.

The land around Alcântara is covered by water (35%), trees (29%) and mangroves (27%) within 3 km, water (53%) and trees (33%) within 16 km, and water (38%) and trees (35%) within 80 km.

3 km
58 m
16 km
64 m
80 km
102 m
treesgrasslandartificial surfaceswaterwetlandmangroves
September weather nearby: São Luís 19 km · Raposa 35 km · Paço do Lumiar 37 km · Bequimão 41 km · São José de Ribamar 43 km · São Bento 55 km · Icatu 57 km · Palmeirândia 60 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 Alcântara (-2.4041°, -44.4167°, elevation 32 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).