Porto Grande weather in September

In September, Porto Grande sees average daytime highs of 34°C and overnight lows near 23°C, with 17 mm of rain across 4.3 wet days and about 12 hours of daylight. It is the 3rd-warmest and 11th-wettest month of the year here.

Day-to-day highs hold fairly steady near 34°C through the month. The sky is clear or mostly clear about 65% 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 Porto Grande's 1st-clearest and 3rd-windiest month. For the whole year in context, see Porto Grande's year-round climate.

Daytime high
34°
3rd warmest
Overnight low
23°
6th coldest
Rainfall
17 mm
4.3 wet days
Daylight
12 hours
6:20 AM – 6:20 PM
Cloud cover
39%
1st clearest
Wind
10 km/h
3rd windiest
Solar energy
6.14 kWh/m²
Travel score
3.6
out of 10

Temperature in September

Average highAverage lowShaded bands: 10–90% of days

Day-to-day highs hold fairly steady near 34°C through the month.

A typical September day in Porto Grande reaches about 34°C in the afternoon and slips back to 23°C overnight — a 11°C spread between the day's warmth and the night's chill. On most days the high lands between 32°C and 35°C. Set against its neighbours, September runs about 2°C warmer than August and about 1°C cooler than October.

20°25°30°35°40°151015202530
Avg high (°C)Avg low (°C)
13323
23323
33323
43323
53323
63323
73423
83423
93423
103423
113423
123423
133423
143423
153423
163423
173423
183423
193423
203423
213423
223423
233423
243423
253423
263423
273523
283523
293523
303523

How September really feels in Porto Grande

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.

Porto Grande weather by month

How September compares with the rest of the year at a glance. September is the 3rd-warmest and 11th-wettest month here — the current month is highlighted below.

MonthHigh / Low (°C)Rainfall (mm)Wet daysDaylight (hours)Travel score
Jan30° / 23°19327.1122.9
Feb29° / 23°23924.9123.0
Mar30° / 23°25627.1123.0
Apr30° / 23°27128122.8
May30° / 23°24528.6122.8
Jun30° / 22°12725123.1
Jul31° / 22°9321.6123.5
Aug32° / 23°4212123.9
Sep34° / 23°174.3123.6
Oct35° / 23°153.4123.1
Nov34° / 23°316.6123.0
Dec32° / 23°10419.5123.0

Cloud cover in September

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 65% of the time in September, the clearest month of the year.

Beyond those clear spells, partly cloudy skies cover about 20% of September, with mostly cloudy or overcast conditions the remaining 15%.

0%25%50%75%100%151015202530
Clearer (%)Cloudier (%)
18911
28911
38911
48911
58713
68713
78713
88713
98713
108713
118515
128515
138515
148515
158416
168416
178416
188317
198317
208317
218317
228317
238317
248317
258317
268317
278317
288317
298218
308119

Chance of precipitation in September

Any precipitation

Porto Grande gets around 17 mm of rain over 4.3 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 15% and peaks near 20% on the wettest days. The odds ease toward the end of the month.

0%10%20%30%151015202530
Rain chance (%)
120
219
319
419
519
619
719
819
919
1019
1118
1218
1318
1417
1517
1616
1715
1814
1913
2012
2112
2211
2311
2410
2510
269
279
289
299
309

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 79% of days. Sticky, muggy-or-worse air turns up on roughly 100% of them.

0%25%50%75%100%151015202530
Muggy (%)Oppressive (%)Miserable (%)
18911
29901
310891
411881
512871
613861
714851
815841
916831
1017821
1117821
1218811
1319801
1420791
1520791
1621781
1722771
1823770
1924760
2024760
2125750
2226740
2327730
2428720
2529710
2630700
2731690
2831690
2932680
3032680

Wind in September

Winds average 10 km/h in September.

Across September, daily wind ranges from about 9 km/h on the calmest days to 11 km/h at its breeziest. It stays fairly steady from day to day.

051015151015202530
Wind speed (km/h)Feels
19calm
29calm
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
2811calm
2911calm
3011calm

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 6:25 AM to 6:15 AM, and sunset from 6:26 PM to 6:15 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202530
Daylight (h)Sunrise (AM)Sunset (PM)
112.06:256:26
212.06:256:25
312.06:246:25
412.06:246:25
512.06:246:24
612.06:236:24
712.06:236:24
812.06:236:23
912.06:226:23
1012.06:226:22
1112.06:226:22
1212.06:216:22
1312.06:216:21
1412.06:216:21
1512.06:206:20
1612.06:206:20
1712.06:206:20
1812.06:196:19
1912.06:196:19
2012.06:186:19
2112.06:186:18
2212.06:186:18
2312.06:176:17
2412.06:176:17
2512.06:176:17
2612.06:166:16
2712.06:166:16
2812.06:166:16
2912.06:156:15
3012.06:156:15

Solar energy in September

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in September, about 6.14 kWh/m².

For context, solar energy here swings from a low near 3.67 kWh/m² to a high of 6.23 kWh/m² in October across the year — September's 6.14 kWh/m² sits near the top of that range.

0246151015202530
Solar energy (kWh/m²)Level
15.9Bright
25.9Bright
35.9Bright
46.0Bright
56.0Bright
66.0Intense
76.0Intense
86.0Intense
96.0Intense
106.1Intense
116.1Intense
126.1Intense
136.1Intense
146.1Intense
156.1Intense
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 Porto Grande

In seasonPeak

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

Porto Grande's monsoon runs January–June, 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 Porto Grande?

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

3.6
Sightseeing
2nd-best month of the year
7.0
Beach & pool
1st-best month of the year

September is a weaker month for outdoor sightseeing in Porto Grande. The water and warmth also suit a beach or pool day.

What to pack for Porto Grande in September

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

In September, Porto Grande sees daytime highs around 34°C and nights near 23°C. Pack light clothes and sun protection. About 4 days see rain.

light clothessun protection

UV index in Porto Grande 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 Porto Grande peaks around February 22 at about 15 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near August 10 at about 11 (extreme).

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

025710JanFebMarAprMayJunJulAugSepOctNovDecExtremeFeb 22UV 15Aug 10UV 11
UV index (midday)Level
Jan13Extreme
Feb15Extreme
Mar15Extreme
Apr14Extreme
May12Extreme
Jun11Extreme
Jul11Extreme
Aug11Extreme
Sep12Extreme
Oct12Extreme
Nov11Extreme
Dec11Extreme

Air quality in Porto Grande 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 Porto Grande is worst in February — around 20 µg/m³ PM2.5 (moderate), about 2.6× the cleanest month (July, 8 µg/m³).

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

0102030JanFebMarAprMayJunJulAugSepOctNovDecModerateGoodModerateFeb 2020 µg/m³Jul 218 µg/m³
PM2.5 (µg/m³)Level
Jan17Moderate
Feb20Moderate
Mar19Moderate
Apr17Moderate
May10Good
Jun8Good
Jul8Good
Aug8Good
Sep10Good
Oct14Moderate
Nov14Moderate
Dec15Moderate
Location & terrain

Where is Porto Grande?

Porto Grande sits at 0.7°N, 51.4°W, 68 m above sea level, in Brazil. The nearest listed city is Macapá, 84 km away.

Anajás

Topography around Porto Grande

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

Within 3 km, the terrain around Porto Grande has only modest variations in elevation — a maximum elevation change of 59 m around an average of 74 m above sea level; within 16 km, only modest variations in elevation — a maximum elevation change of 177 m; within 80 km, significant variations in elevation — a maximum elevation change of 440 m.

The land around Porto Grande is covered by trees (40%) and grassland (34%) within 3 km, trees (73%) and grassland (22%) within 16 km, and trees (78%) within 80 km.

3 km
59 m
16 km
177 m
80 km
440 m
treesgrasslandartificial surfacesbare terrainwaterwetland
September weather nearby: Macapá 84 km · Santana 88 km · Mazagão 93 km · Afuá 150 km · Chaves 186 km · Laranjal do Jari 210 km · Gurupá 237 km · Anajás 250 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 Porto Grande (0.7133°, -51.4133°, elevation 68 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).