Santo Antônio weather in September

In September, Santo Antônio sees average daytime highs of 30°C and overnight lows near 22°C, with 8 mm of rain across 2.9 wet days and about 12 hours of daylight. It is the 8th-warmest and 11th-wettest month of the year here.

Day-to-day highs hold fairly steady near 30°C through the month. The sky is clear or mostly clear about 44% of the time in September, and the air most often feels muggy.

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's 1st-clearest and 1st-windiest month. For the whole year in context, see Santo Antônio's year-round climate.

Daytime high
30°
8th warmest
Overnight low
22°
3rd coldest
Rainfall
8 mm
2.9 wet days
Daylight
12 hours
5:17 AM – 5:15 PM
Cloud cover
43%
1st clearest
Wind
18 km/h
1st windiest
Solar energy
5.77 kWh/m²
Travel score
6.0
out of 10

Santo Antônio 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 30°C through the month.

A typical September day in Santo Antônio reaches about 30°C in the afternoon and slips back to 22°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 31°C. Set against its neighbours, September runs about 1°C warmer than August and about 1°C cooler than October.

20°25°30°35°151015202530
Avg high (°C)Avg low (°C)
13021
23022
33022
43022
53022
63022
73022
83022
93022
103022
113022
123022
133022
143022
153022
163022
173022
183022
193022
203022
213022
223022
233022
243022
253022
263122
273122
283122
293122
303122

How September really feels in Santo Antônio

Once humidity and wind are folded in, September averages 9 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
9
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 weather by month

How September compares with the rest of the year at a glance. September is the 8th-warmest and 11th-wettest month here — the current month is highlighted below.

MonthHigh / Low (°C)Rainfall (mm)Wet daysDaylight (hours)Travel score
Jan31° / 24°4311.712.34.1
Feb31° / 24°5312.212.23.9
Mar31° / 24°7716.9123.7
Apr31° / 23°881611.94.0
May30° / 23°6212.511.74.8
Jun29° / 22°5411.611.65.4
Jul28° / 21°438.811.76.0
Aug29° / 21°164.811.86.2
Sep30° / 22°82.9126.0
Oct31° / 23°7212.15.5
Nov31° / 23°92.912.35.2
Dec32° / 24°186.812.44.7

Cloud cover in September

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 44% of the time in September, the clearest month of the year.

Beyond those clear spells, partly cloudy skies cover about 39% of September, with mostly cloudy or overcast conditions the remaining 16%. Skies tend to open up as the month goes on.

0%25%50%75%100%151015202530
Clearer (%)Cloudier (%)
18020
28020
38020
48020
58020
68020
78020
88020
98218
108218
118218
128218
138218
148317
158317
168317
178416
188416
198614
208614
218614
228713
238713
248812
258812
268713
278713
288713
298812
308713

Chance of precipitation in September

Any precipitation

Santo Antônio gets around 8 mm of rain over 2.9 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 10% and peaks near 13% on the wettest days. The odds ease toward the end of the month.

0%10%20%30%151015202530
Rain chance (%)
113
213
313
413
513
612
712
812
912
1012
1111
1211
1311
1410
1510
1610
179
189
198
208
218
228
237
247
257
267
276
286
296
306

Humidity in September

DryComfortableHumidMuggyOppressiveMiserable

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

By dew point, September lands in the muggy band about 87% of days. Sticky, muggy-or-worse air turns up on roughly 93% of them.

0%25%50%75%100%151015202530
Humid (%)Muggy (%)Oppressive (%)
19865
29856
39856
49856
59856
69856
79856
89856
99856
109856
119856
128866
138866
148866
157885
167885
177885
186895
196895
206895
215905
225905
235905
245896
255896
265896
275896
285887
295887
305887

Wind in September

Winds average 18 km/h in September, the windiest month of the year.

Across September, daily wind ranges from about 17 km/h on the calmest days to 18 km/h at its breeziest. It stays fairly steady from day to day.

05101520151015202530
Wind speed (km/h)Feels
118light breeze
218light breeze
318light breeze
418light breeze
518light breeze
618light breeze
718light breeze
818light breeze
918light breeze
1018light breeze
1118light breeze
1218light breeze
1318light breeze
1418light breeze
1518light breeze
1618light breeze
1718light breeze
1818light 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 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 5:25 AM to 5:10 AM, and sunset from 5:18 PM to 5:13 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202530
Daylight (h)Sunrise (AM)Sunset (PM)
111.95:255:18
211.95:255:18
311.95:245:18
411.95:245:17
511.95:235:17
611.95:235:17
711.95:225:17
811.95:225:17
911.95:215:17
1011.95:215:16
1111.95:205:16
1211.95:195:16
1311.95:195:16
1412.05:185:16
1512.05:185:15
1612.05:175:15
1712.05:175:15
1812.05:165:15
1912.05:165:15
2012.05:155:14
2112.05:155:14
2212.05:145:14
2312.05:135:14
2412.05:135:14
2512.05:125:14
2612.05:125:13
2712.05:115:13
2812.05:115:13
2912.05:105:13
3012.05:105:13

Solar energy in September

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in September, about 5.77 kWh/m².

For context, solar energy here swings from a low near 4.3 kWh/m² to a high of 6.26 kWh/m² in November across the year — September's 5.77 kWh/m² falls in the middle.

0246151015202530
Solar energy (kWh/m²)Level
15.4Bright
25.4Bright
35.4Bright
45.5Bright
55.5Bright
65.5Bright
75.5Bright
85.5Bright
95.6Bright
105.6Bright
115.6Bright
125.6Bright
135.7Bright
145.7Bright
155.7Bright
165.8Bright
175.8Bright
185.8Bright
195.8Bright
205.9Bright
215.9Bright
225.9Bright
236.0Bright
246.0Bright
256.0Intense
266.0Intense
276.1Intense
286.1Intense
296.1Intense
306.1Intense
Planning a trip in September

Is September a good time to visit Santo Antônio?

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

6.0
Sightseeing
2nd-best month of the year
8.2
Beach & pool
1st-best month of the year

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

What to pack for Santo Antônio in September

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

In September, Santo Antônio sees daytime highs around 30°C and nights near 22°C. Pack light clothes. Worth having: sun protection.

light clothessun protection

Sea temperature near Santo Antônio in September

The nearest coast averages about 26°C in September — the other half of the beach question. The full-year curve and swim-comfort zones are below.

The sea at the nearest coast (about 62 km away) is warmest in March at about 29°C and coldest in August near 26°C.

The water stays above 20°C all year — warm enough for a swim any month.

24°26°28°30°JanFebMarAprMayJunJulAugSepOctNovDecwarmtropicalcomfortable to swim
Sea temperature (°C)Comfort
Jan28Tropical
Feb28Tropical
Mar29Tropical
Apr29Tropical
May28Tropical
Jun27Warm
Jul27Warm
Aug26Warm
Sep26Warm
Oct27Warm
Nov27Warm
Dec28Warm

UV index in Santo Antônio 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 Santo Antônio peaks around March 12 at about 15 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near July 15 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 12UV 15Jul 15UV 10
UV index (midday)Level
Jan13Extreme
Feb15Extreme
Mar15Extreme
Apr14Extreme
May11Extreme
Jun10Very high
Jul10Very high
Aug10Extreme
Sep12Extreme
Oct12Extreme
Nov12Extreme
Dec12Extreme
Location & terrain

Where is Santo Antônio?

Santo Antônio sits at 6.3°S, 35.5°W, 93 m above sea level, in Brazil. The nearest listed city is Nova Cruz, 19 km away.

Topography around Santo Antônio

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

Within 3 km, the terrain around Santo Antônio has only modest variations in elevation — a maximum elevation change of 44 m around an average of 89 m above sea level; within 16 km, only modest variations in elevation — a maximum elevation change of 149 m; within 80 km, large variations in elevation — a maximum elevation change of 686 m.

The land around Santo Antônio is covered by grassland (88%) within 3 km, grassland (87%) within 16 km, and grassland (45%) and shrubs (26%) within 80 km.

3 km
44 m
16 km
149 m
80 km
686 m
treesshrubsgrasslandcroplandartificial surfaceswatermangroves
September weather nearby: Nova Cruz 19 km · Goianinha 30 km · Monte Alegre 31 km · São José de Mipibu 37 km · Nísia Floresta 39 km · Canguaretama 39 km · Araruna 40 km · Belém 43 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 (-6.3106°, -35.4789°, elevation 93 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. Topography is sampled from the Copernicus DEM GLO-90 elevation model (© ESA/Airbus) and ESA WorldCover 2021 land cover (CC BY 4.0).