Santo Antônio do Içá weather in September

In September, Santo Antônio do Içá sees average daytime highs of 31°C and overnight lows near 23°C, with 143 mm of rain across 23 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 31°C through the month. The sky is clear or mostly clear about 11% of the time in September, and the air most often feels miserable.

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 Santo Antônio do Içá's 3rd-clearest and 8th-windiest month. For the whole year in context, see Santo Antônio do Içá's year-round climate.

Daytime high
31°
2nd warmest
Overnight low
23°
5th coldest
Rainfall
143 mm
23 wet days
Daylight
12 hours
6:27 AM – 6:26 PM
Cloud cover
71%
3rd clearest
Wind
4 km/h
8th windiest
Solar energy
5.18 kWh/m²
Travel score
2.9
out of 10

Santo Antônio do Içá is human settlement in 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 Santo Antônio do Içá reaches about 31°C in the afternoon and slips back to 23°C overnight — a 8°C spread between the day's warmth and the night's chill. On most days the high lands between 29°C and 33°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)
13123
23123
33123
43123
53123
63123
73123
83123
93123
103123
113123
123123
133123
143123
153123
163123
173123
183123
193123
203123
213123
223123
233123
243123
253123
263123
273123
283123
293123
303223

How September really feels in Santo Antônio do Içá

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.

Santo Antônio do Içá 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
Jan30° / 24°27728.312.22.7
Feb30° / 24°27625.512.12.7
Mar30° / 24°32329.1122.6
Apr30° / 23°32628.211.92.7
May30° / 23°30128.811.92.9
Jun29° / 23°20626.111.83.2
Jul30° / 22°15424.811.83.4
Aug31° / 23°13023.311.93.3
Sep31° / 23°14323122.9
Oct31° / 24°18825.612.12.7
Nov31° / 24°21926.212.12.6
Dec31° / 24°26628.812.22.6

Cloud cover in September

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 11% of the time in September.

Beyond those clear spells, partly cloudy skies cover about 21% of September, with mostly cloudy or overcast conditions the remaining 68%.

0%25%50%75%100%151015202530
Clearer (%)Cloudier (%)
13763
23664
33664
43565
53565
63565
73466
83466
93466
103367
113367
123268
133268
143268
153268
163268
173268
183268
193268
203169
213070
223070
233070
243070
252872
262872
272773
282674
292575
302476

Chance of precipitation in September

Any precipitation

Santo Antônio do Içá gets around 143 mm of rain over 23 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 76% and peaks near 78% on the wettest days.

0%20%40%60%80%151015202530
Rain chance (%)
177
277
376
476
576
675
775
875
974
1074
1174
1275
1375
1475
1575
1676
1776
1877
1977
2078
2178
2278
2378
2478
2578
2678
2778
2878
2978
3078

Humidity in September

DryComfortableHumidMuggyOppressiveMiserable

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

By dew point, September lands in the miserable band about 61% of days. Sticky, muggy-or-worse air turns up on roughly 100% of them.

0%25%50%75%100%151015202530
Muggy (%)Oppressive (%)Miserable (%)
114851
204753
304753
404753
514653
614653
714554
814455
914455
1014356
1114257
1214158
1314059
1413960
1513861
1613762
1713663
1803664
1903565
2003565
2103466
2203466
2303367
2403367
2503367
2603367
2703268
2803268
2903268
3003169

Wind in September

Winds average 4 km/h in September.

Across September, daily wind ranges from about 4 km/h on the calmest days to 4 km/h at its breeziest. It stays fairly steady from day to day.

0246810151015202530
Wind speed (km/h)Feels
14calm
24calm
34calm
44calm
54calm
64calm
74calm
84calm
94calm
104calm
114calm
124calm
134calm
144calm
154calm
164calm
174calm
184calm
194calm
204calm
214calm
224calm
234calm
244calm
254calm
264calm
274calm
284calm
294calm
304calm

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 6:33 AM to 6:20 AM, and sunset from 6:30 PM to 6:22 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202530
Daylight (h)Sunrise (AM)Sunset (PM)
111.96:336:30
211.96:336:29
311.96:326:29
411.96:326:29
512.06:326:29
612.06:316:28
712.06:316:28
812.06:306:28
912.06:306:28
1012.06:296:27
1112.06:296:27
1212.06:286:27
1312.06:286:26
1412.06:286:26
1512.06:276:26
1612.06:276:26
1712.06:266:25
1812.06:266:25
1912.06:256:25
2012.06:256:24
2112.06:246:24
2212.06:246:24
2312.06:236:24
2412.06:236:23
2512.06:236:23
2612.06:226:23
2712.06:226:23
2812.06:216:22
2912.06:216:22
3012.06:206:22

Solar energy in September

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in September, about 5.18 kWh/m².

For context, solar energy here swings from a low near 3.72 kWh/m² to a high of 5.19 kWh/m² in October across the year — September's 5.18 kWh/m² sits near the top of that range.

0246151015202530
Solar energy (kWh/m²)Level
15.0Bright
25.0Bright
35.0Bright
45.1Bright
55.1Bright
65.1Bright
75.1Bright
85.1Bright
95.1Bright
105.1Bright
115.1Bright
125.2Bright
135.2Bright
145.2Bright
155.2Bright
165.2Bright
175.2Bright
185.2Bright
195.2Bright
205.2Bright
215.2Bright
225.2Bright
235.2Bright
245.3Bright
255.3Bright
265.3Bright
275.3Bright
285.3Bright
295.3Bright
305.3Bright
Planning a trip in September

Is September a good time to visit Santo Antônio do Içá?

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

2.9
Sightseeing
4th-best month of the year
4.5
Beach & pool
3rd-best month of the year

September is a weaker month for outdoor sightseeing in Santo Antônio do Içá.

What to pack for Santo Antônio do Içá in September

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

In September, Santo Antônio do Içá sees daytime highs around 31°C and nights near 23°C. Pack light clothes and rain gear. Worth having: sun protection. About 23 days see rain.

light clothesrain gearsun protection

UV index in Santo Antônio do Içá in September

LowModerateHighVery highExtreme

Clear-sky midday UV in September 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 Santo Antônio do Içá peaks around March 10 at about 15 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near September 9 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 10UV 15Sep 9UV 10
UV index (midday)Level
Jan15Extreme
Feb15Extreme
Mar15Extreme
Apr14Extreme
May13Extreme
Jun11Extreme
Jul10Very high
Aug10Very high
Sep10Very high
Oct12Extreme
Nov13Extreme
Dec12Extreme

Air quality in Santo Antônio do Içá 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 Santo Antônio do Içá is worst in August — around 18 µg/m³ PM2.5 (moderate), about 1.9× the cleanest month (June, 9 µg/m³).

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

01020JanFebMarAprMayJunJulAugSepOctNovDecModerateGoodModerateAug 2118 µg/m³Jun 1310 µg/m³
PM2.5 (µg/m³)Level
Jan14Moderate
Feb15Moderate
Mar16Moderate
Apr13Moderate
May10Good
Jun9Good
Jul11Good
Aug18Moderate
Sep16Moderate
Oct13Moderate
Nov13Moderate
Dec12Moderate
Location & terrain

Where is Santo Antônio do Içá?

Santo Antônio do Içá sits at 3.1°S, 67.9°W, 68 m above sea level, in Brazil. The nearest listed city is Tonantins, 30 km away.

LeticiaTabatingaBenjamin ConstantAtalaia do Norte

Topography around Santo Antônio do Içá

How much the land rises and falls, and what covers it, within 3, 16 and 80 km of Santo Antônio do Içá.

Within 3 km, the terrain around Santo Antônio do Içá has only modest variations in elevation — a maximum elevation change of 61 m around an average of 65 m above sea level; within 16 km, only modest variations in elevation — a maximum elevation change of 73 m; within 80 km, only modest variations in elevation — a maximum elevation change of 92 m.

The land around Santo Antônio do Içá is covered by trees (52%) and water (38%) within 3 km, trees (82%) within 16 km, and trees (96%) within 80 km.

3 km
61 m
16 km
73 m
80 km
92 m
treesgrasslandartificial surfaceswater
September weather nearby: Tonantins 30 km · São Paulo de Olivença 108 km · Fonte Boa 215 km · Carauari 229 km · Leticia 254 km · Tabatinga 255 km · Benjamin Constant 272 km · Atalaia do Norte 287 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 Santo Antônio do Içá (-3.1022°, -67.9397°, 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).