Porto Nacional weather in September

In September, Porto Nacional sees average daytime highs of 36°C and overnight lows near 24°C, with 20 mm of rain across 3.2 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 36°C through the month. The sky is clear or mostly clear about 48% of the time in September, and the air most often feels comfortable.

Daylight stretches from about 11 h 48 min at the start of September to 12 h 06 min by month's end. Set against the rest of the year, September is Porto Nacional's 4th-clearest and 4th-windiest month. For the whole year in context, see Porto Nacional's year-round climate.

Daytime high
36°
1st warmest
Overnight low
24°
12th coldest
Rainfall
20 mm
3.2 wet days
Daylight
11 h 54 min
6:10 AM – 6:06 PM
Cloud cover
43%
4th clearest
Wind
7 km/h
4th windiest
Solar energy
6.16 kWh/m²
Travel score
2.6
out of 10

Temperature in September

Average highAverage lowShaded bands: 10–90% of days

Day-to-day highs hold fairly steady near 36°C through the month.

A typical September day in Porto Nacional reaches about 36°C in the afternoon and slips back to 24°C overnight — a 12°C spread between the day's warmth and the night's chill. On most days the high lands between 33°C and 38°C. Set against its neighbours, September runs on par with August and about 2°C warmer than October.

20°25°30°35°40°151015202530
Avg high (°C)Avg low (°C)
13623
23623
33623
43623
53624
63624
73624
83624
93624
103624
113624
123624
133624
143624
153624
163624
173624
183624
193624
203624
213624
223524
233524
243524
253524
263524
273524
283524
293524
303524

How September really feels in Porto Nacional

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 Nacional weather by month

How September compares with the rest of the year at a glance. September 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
Jan30° / 22°29726.212.63.0
Feb30° / 22°26623.912.42.9
Mar30° / 23°24725.312.13.0
Apr31° / 23°14416.911.83.5
May32° / 23°365.911.54.2
Jun33° / 21°20.311.44.6
Jul33° / 21°00.111.44.4
Aug35° / 22°10.311.63.3
Sep36° / 24°203.211.92.6
Oct34° / 24°11414.512.22.9
Nov31° / 23°2272212.53.0
Dec31° / 23°26124.312.63.0

Cloud cover in September

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 48% of the time in September.

Beyond those clear spells, partly cloudy skies cover about 23% of September, with mostly cloudy or overcast conditions the remaining 29%. Skies tend to cloud over as the month goes on.

0%25%50%75%100%151015202530
Clearer (%)Cloudier (%)
17921
27822
37822
47624
57624
67525
77525
87525
97426
107426
117426
127327
137327
147228
157129
167129
177129
187030
197030
206931
216832
226733
236634
246634
256535
266436
276337
286238
296139
306040

Chance of precipitation in September

Any precipitation

Porto Nacional gets around 20 mm of rain over 3.2 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 11% and peaks near 28% on the wettest days. The odds climb toward the end of the month.

0%10%20%30%40%151015202530
Rain chance (%)
12
23
33
43
53
63
74
84
94
104
115
125
136
146
157
168
179
1811
1912
2013
2115
2216
2318
2419
2521
2623
2724
2826
2927
3028

Humidity in September

DryComfortableHumidMuggyOppressiveMiserable

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

By dew point, September lands in the comfortable band about 26% of days. Sticky, muggy-or-worse air turns up on roughly 30% of them.

0%25%50%75%100%151015202530
Dry (%)Comfortable (%)Humid (%)Muggy (%)Oppressive (%)
130372581
230362581
330352491
4313424101
5313424111
6313323121
7313323121
8313322132
9303322142
10303222152
11293222152
12283122163
13273122173
14263023184
15252923185
16242824196
17222624207
18212525218
19192425229
201822252411
211621262512
221419252714
231317252916
241116253018
251015243220
26914233322
27713223424
28612213426
29612203528
30511193530

Wind in September

Winds average 7 km/h in September.

Across September, daily wind ranges from about 6 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
177calm
187calm
197calm
207calm
217calm
227calm
237calm
247calm
257calm
267calm
277calm
286calm
296calm
306calm

Sunrise & sunset in September

DaylightNight

Daylight runs from about 11 h 48 min at the start of September to 12 h 06 min by month's end. The lit band spans sunrise to sunset each day.

Days grow by about 18 minutes over September. Sunrise moves from 6:20 AM to 6:00 AM, and sunset from 6:07 PM to 6:05 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202530
Daylight (h)Sunrise (AM)Sunset (PM)
111.86:206:07
211.86:196:07
311.86:186:07
411.86:186:07
511.86:176:07
611.86:166:07
711.96:166:07
811.96:156:07
911.96:146:07
1011.96:146:07
1111.96:136:07
1211.96:126:07
1311.96:126:06
1411.96:116:06
1511.96:106:06
1611.96:106:06
1712.06:096:06
1812.06:086:06
1912.06:086:06
2012.06:076:06
2112.06:066:06
2212.06:066:06
2312.06:056:06
2412.06:046:06
2512.06:046:06
2612.06:036:06
2712.16:026:06
2812.16:026:06
2912.16:016:06
3012.16:006:05

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 — the sunniest month for solar.

For context, solar energy here swings from a low near 4.96 kWh/m² to a high of 6.16 kWh/m² in September across the year — September's 6.16 kWh/m² sits near the top of that range.

0246151015202530
Solar energy (kWh/m²)Level
16.1Intense
26.1Intense
36.1Intense
46.2Intense
56.2Intense
66.2Intense
76.2Intense
86.2Intense
96.2Intense
106.2Intense
116.2Intense
126.2Intense
136.2Intense
146.2Intense
156.2Intense
166.2Intense
176.2Intense
186.2Intense
196.2Intense
206.2Intense
216.2Intense
226.1Intense
236.1Intense
246.1Intense
256.1Intense
266.1Intense
276.1Intense
286.1Intense
296.1Intense
306.1Intense
Planning a trip in September

Hazard calendar for Porto Nacional

In seasonPeak

None of Porto Nacional'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 Nacional's monsoon runs November–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 Porto Nacional?

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

2.6
Sightseeing
12th-best month of the year
5.9
Beach & pool
5th-best month of the year

September is a weaker month for outdoor sightseeing in Porto Nacional.

What to pack for Porto Nacional in September

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

In September, Porto Nacional sees daytime highs around 36°C and nights near 24°C. Pack light clothes and sun protection. About 3 days see rain.

light clothessun protection

UV index in Porto Nacional 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 Nacional peaks around February 15 at about 15 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near June 22 at about 9 (very high).

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

025710JanFebMarAprMayJunJulAugSepOctNovDecExtremeVery highExtremeFeb 15UV 15Jun 22UV 9
UV index (midday)Level
Jan14Extreme
Feb15Extreme
Mar14Extreme
Apr12Extreme
May10Extreme
Jun9Very high
Jul9Very high
Aug10Extreme
Sep12Extreme
Oct10Very high
Nov13Extreme
Dec12Extreme

Air quality in Porto Nacional 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 Nacional is worst in September — around 35 µg/m³ PM2.5 (moderate), about 4.2× the cleanest month (May, 8 µg/m³).

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

010203040JanFebMarAprMayJunJulAugSepOctNovDecGoodModerateSep 1934 µg/m³May 208 µg/m³
PM2.5 (µg/m³)Level
Jan10Good
Feb9Good
Mar11Good
Apr10Good
May8Good
Jun9Good
Jul9Good
Aug20Moderate
Sep35Moderate
Oct28Moderate
Nov14Moderate
Dec11Good
Location & terrain

Where is Porto Nacional?

Porto Nacional sits at 10.7°S, 48.4°W, 231 m above sea level, in Brazil. The nearest listed city is Palmas, 61 km away.

Topography around Porto Nacional

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

Within 3 km, the terrain around Porto Nacional has only modest variations in elevation — a maximum elevation change of 69 m around an average of 226 m above sea level; within 16 km, significant variations in elevation — a maximum elevation change of 386 m; within 80 km, significant variations in elevation — a maximum elevation change of 534 m.

The land around Porto Nacional is covered by water (46%) and artificial surfaces (25%) within 3 km, grassland (43%) and trees (25%) within 16 km, and trees (44%) and grassland (38%) within 80 km.

3 km
69 m
16 km
386 m
80 km
534 m
treesshrubsgrasslandcroplandartificial surfaceswaterwetland
September weather nearby: Palmas 61 km · Paraíso do Tocantins 77 km · Miracema do Tocantins 127 km · Lagoa da Confusão 132 km · Gurupi 134 km · Formoso do Araguaia 171 km · Dianópolis 202 km · Guaraí 209 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 Nacional (-10.7081°, -48.4172°, elevation 231 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).