São João da Barra weather in September

In September, São João da Barra sees average daytime highs of 25°C and overnight lows near 21°C, with 48 mm of rain across 8.1 wet days and about 11.9 hours of daylight. It is the 10th-warmest and 9th-wettest month of the year here.

Day-to-day highs hold fairly steady near 25°C through the month. The sky is clear or mostly clear about 46% of the time in September, and the air most often feels muggy.

Daylight stretches from about 11 h 36 min at the start of September to 12 h 12 min by month's end. Set against the rest of the year, September is São João da Barra's 6th-clearest and 1st-windiest month. For the whole year in context, see São João da Barra's year-round climate.

Daytime high
25°
10th warmest
Overnight low
21°
4th coldest
Rainfall
48 mm
8.1 wet days
Daylight
11 h 54 min
6:42 AM – 6:35 PM
Cloud cover
48%
6th clearest
Wind
22 km/h
1st windiest
Solar energy
5.12 kWh/m²
Travel score
7.5
out of 10

São João da Barra is 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 25°C through the month.

A typical September day in São João da Barra reaches about 25°C in the afternoon and slips back to 21°C overnight — a 4°C spread between the day's warmth and the night's chill. On most days the high lands between 22°C and 26°C. Set against its neighbours, September runs on par with August and on par with October.

15°20°25°30°151015202530
Avg high (°C)Avg low (°C)
12421
22421
32421
42421
52421
62421
72421
82421
92421
102421
112421
122421
132421
142421
152521
162521
172521
182521
192521
202521
212521
222521
232521
242521
252521
262521
272521
282521
292521
302521

São João da Barra weather by month

How September compares with the rest of the year at a glance. September is the 10th-warmest and 9th-wettest month here — the current month is highlighted below.

MonthHigh / Low (°C)Rainfall (mm)Wet daysDaylight (hours)Travel score
Jan27° / 24°11410.413.26.3
Feb28° / 24°547.612.76.5
Mar28° / 24°11212.712.26.0
Apr27° / 23°7511.411.56.5
May25° / 22°519.6117.1
Jun25° / 21°256.310.77.8
Jul24° / 20°296.510.88.0
Aug24° / 20°26611.38.0
Sep25° / 21°488.111.97.5
Oct25° / 22°788.812.57.0
Nov26° / 23°13913.8135.9
Dec27° / 24°15114.313.35.8

Cloud cover in September

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 46% of the time in September.

Beyond those clear spells, partly cloudy skies cover about 15% of September, with mostly cloudy or overcast conditions the remaining 40%. Skies tend to cloud over as the month goes on.

0%25%50%75%100%151015202530
Clearer (%)Cloudier (%)
17129
27129
37129
47030
57030
67030
76931
86832
96733
106634
116535
126436
136337
146238
156040
165941
175842
185743
195743
205644
215545
225446
235347
245248
255248
265149
275149
285050
295050
304951

Chance of precipitation in September

Any precipitation

São João da Barra gets around 48 mm of rain over 8.1 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 26% and peaks near 29% on the wettest days. The odds climb toward the end of the month.

0%10%20%30%40%151015202530
Rain chance (%)
120
221
321
422
522
623
724
824
925
1025
1126
1226
1326
1426
1527
1627
1727
1827
1928
2028
2128
2228
2329
2429
2529
2629
2729
2829
2929
3029

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 57% of days. Sticky, muggy-or-worse air turns up on roughly 63% of them.

0%25%50%75%100%151015202530
Dry (%)Comfortable (%)Humid (%)Muggy (%)Oppressive (%)
131225591
231225591
331224601
431224601
531224592
631224592
731224592
831224592
931224592
1031124602
1121124612
1221124603
1321124603
1421024613
1521024613
1621024604
172924614
182924605
192924605
202924596
212924587
222924578
232925559
2439255310
2539255211
2639245212
2738245213
2838245114
2938244915
3038234916

Wind in September

Winds average 22 km/h in September, the windiest month of the year.

Across September, daily wind ranges from about 21 km/h on the calmest days to 22 km/h at its breeziest. It stays fairly steady from day to day.

0510152025151015202530
Wind speed (km/h)Feels
121breezy
221breezy
321breezy
422breezy
522breezy
622breezy
722breezy
822breezy
922breezy
1022breezy
1122breezy
1222breezy
1322breezy
1422breezy
1522breezy
1622breezy
1722breezy
1822breezy
1922breezy
2022breezy
2122breezy
2222breezy
2322breezy
2422breezy
2522breezy
2621breezy
2721breezy
2821breezy
2921breezy
3021breezy

Sunrise & sunset in September

DaylightNight

Daylight runs from about 11 h 36 min at the start of September to 12 h 12 min by month's end. The lit band spans sunrise to sunset each day.

Days grow by about 36 minutes over September. Sunrise moves from 6:57 AM to 6:28 AM, and sunset from 6:31 PM to 6:39 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202530
Daylight (h)Sunrise (AM)Sunset (PM)
111.66:576:31
211.66:566:31
311.66:556:31
411.66:546:32
511.66:536:32
611.76:526:32
711.76:516:32
811.76:506:33
911.76:496:33
1011.86:486:33
1111.86:476:34
1211.86:466:34
1311.86:456:34
1411.86:446:34
1511.96:436:35
1611.96:426:35
1711.96:416:35
1811.96:406:35
1911.96:396:36
2012.06:386:36
2112.06:376:36
2212.06:366:36
2312.06:356:37
2412.06:346:37
2512.16:336:37
2612.16:326:38
2712.16:316:38
2812.16:306:38
2912.26:296:38
3012.26:286:39

Solar energy in September

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in September, about 5.12 kWh/m².

For context, solar energy here swings from a low near 3.64 kWh/m² to a high of 6.72 kWh/m² in February across the year — September's 5.12 kWh/m² falls in the middle.

0246151015202530
Solar energy (kWh/m²)Level
14.9Bright
25.0Bright
35.0Bright
45.0Bright
55.0Bright
65.0Bright
75.0Bright
85.1Bright
95.1Bright
105.1Bright
115.1Bright
125.1Bright
135.1Bright
145.1Bright
155.1Bright
165.1Bright
175.1Bright
185.1Bright
195.2Bright
205.2Bright
215.2Bright
225.2Bright
235.2Bright
245.2Bright
255.2Bright
265.2Bright
275.3Bright
285.3Bright
295.3Bright
305.3Bright
Planning a trip in September

Hazard calendar for São João da Barra

In seasonPeak

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

São João da Barra's rainy season runs October–January, when most of the year's rain falls.

Rainy season
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec

Is September a good time to visit São João da Barra?

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

7.5
Sightseeing
4th-best month of the year
6.5
Beach & pool
8th-best month of the year

September is one of the better times to visit São João da Barra for general sightseeing. The water and warmth also suit a beach or pool day.

What to pack for São João da Barra in September

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

In September, São João da Barra sees daytime highs around 25°C and nights near 21°C. Worth packing: light clothes, rain gear, sun protection and a windbreaker. About 8 days see rain.

light clothesrain gearsun protectiona windbreaker

Sea temperature near São João da Barra in September

The nearest coast averages about 22°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 18 km away) is warmest in March at about 25°C and coldest in August near 22°C.

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

20°22°24°26°JanFebMarAprMayJunJulAugSepOctNovDecrefreshingwarmcomfortable to swim
Sea temperature (°C)Comfort
Jan24Warm
Feb25Warm
Mar25Warm
Apr25Warm
May24Warm
Jun23Refreshing
Jul23Refreshing
Aug22Refreshing
Sep22Refreshing
Oct23Refreshing
Nov24Refreshing
Dec24Warm

UV index in São João da Barra in September

LowModerateHighVery highExtreme

Clear-sky midday UV in September peaks around 9 (very high — sun protection essential). The full-year curve, shaded by WHO exposure level, is below.

Under clear skies, the midday UV index in São João da Barra peaks around February 9 at about 14 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near June 23 at about 6 (high).

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

025710JanFebMarAprMayJunJulAugSepOctNovDecExtremeVery highHighVery highExtremeFeb 9UV 14Jun 23UV 6
UV index (midday)Level
Jan14Extreme
Feb14Extreme
Mar12Extreme
Apr9Very high
May7High
Jun6High
Jul6High
Aug8Very high
Sep9Very high
Oct12Extreme
Nov13Extreme
Dec13Extreme
Location & terrain

Where is São João da Barra?

São João da Barra sits at 21.6°S, 41.1°W, 7 m above sea level, in Brazil. The nearest listed city is Campos dos Goytacazes, 31 km away.

Topography around São João da Barra

How much the land rises and falls, and what covers it, within 3, 16 and 80 km of São João da Barra.

Within 3 km, the terrain around São João da Barra has only modest variations in elevation — a maximum elevation change of 11 m around an average of 2 m above sea level; within 16 km, only modest variations in elevation — a maximum elevation change of 19 m; within 80 km, very significant variations in elevation — a maximum elevation change of 1,525 m.

The land around São João da Barra is covered by grassland (59%) within 3 km, water (47%) and grassland (37%) within 16 km, and grassland (44%) and water (38%) within 80 km.

3 km
11 m
16 km
19 m
80 km
1,525 m
treesgrasslandcroplandartificial surfacesbare terrainwaterwetlandmangroves
September weather nearby: Campos dos Goytacazes 31 km · São Francisco de Itabapoana 39 km · Quissamã 68 km · Marataizes 70 km · Mimoso do Sul 72 km · São Fidélis 72 km · Itapemirim 73 km · Bom Jesus do Itabapoana 86 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 São João da Barra (-21.6403°, -41.0511°, elevation 7 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).