Itaboraí weather in September

In September, Itaboraí sees average daytime highs of 26°C and overnight lows near 19°C, with 82 mm of rain across 10.9 wet days and about 11.9 hours of daylight. It is the 8th-warmest and 8th-wettest month of the year here.

Day-to-day highs hold fairly steady near 26°C through the month. The sky is clear or mostly clear about 38% of the time in September, and the air most often feels humid.

Daylight stretches from about 11 h 30 min at the start of September to 12 h 12 min by month's end. Set against the rest of the year, September is Itaboraí's 6th-clearest and 2nd-windiest month. For the whole year in context, see Itaboraí's year-round climate.

Daytime high
26°
8th warmest
Overnight low
19°
4th coldest
Rainfall
82 mm
10.9 wet days
Daylight
11 h 54 min
6:50 AM – 6:42 PM
Cloud cover
55%
6th clearest
Wind
8 km/h
2nd windiest
Solar energy
4.69 kWh/m²
Travel score
6.5
out of 10

Itaboraí is human settlement in Brazil.

Air quality
Good
PM2.5 8 µg/m³ · 2015

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 26°C through the month.

A typical September day in Itaboraí reaches about 26°C in the afternoon and slips back to 19°C overnight — a 8°C spread between the day's warmth and the night's chill. On most days the high lands between 21°C and 31°C. Set against its neighbours, September runs on par with August and about 1°C cooler than October.

15°20°25°30°35°151015202530
Avg high (°C)Avg low (°C)
12618
22618
32618
42618
52618
62618
72618
82618
92718
102718
112718
122718
132719
142719
152719
162719
172719
182619
192619
202619
212619
222619
232619
242619
252619
262619
272619
282619
292719
302719

How September really feels in Itaboraí

Once humidity and wind are folded in, September averages 0 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
0
heat index over the day's high
Days feeling ≤ C
0
wind chill below the day's low

September sits comfortably in between — no days that feel dangerously hot or drop to a hard freeze once humidity and wind are folded in.

Itaboraí weather by month

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

MonthHigh / Low (°C)Rainfall (mm)Wet daysDaylight (hours)Travel score
Jan31° / 23°25921.313.23.4
Feb31° / 23°19918.112.83.5
Mar30° / 23°22021.912.23.8
Apr28° / 21°10814.211.55.4
May26° / 19°771110.96.7
Jun26° / 18°44710.67.4
Jul25° / 17°447.210.77.6
Aug26° / 17°437.311.27.4
Sep26° / 19°8210.911.96.5
Oct27° / 20°11213.512.55.8
Nov28° / 21°21018.713.14.8
Dec29° / 23°25421.613.43.8

Cloud cover in September

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 38% of the time in September.

Beyond those clear spells, partly cloudy skies cover about 12% of September, with mostly cloudy or overcast conditions the remaining 51%. Skies tend to cloud over as the month goes on.

0%25%50%75%100%151015202530
Clearer (%)Cloudier (%)
16436
26436
36337
46337
56139
66139
76040
85941
95743
105644
115545
125446
135248
145149
154951
164852
174753
184654
194456
204357
214258
224159
234060
243961
253862
263862
273862
283862
293763
303763

Chance of precipitation in September

Any precipitation

Itaboraí gets around 82 mm of rain over 10.9 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 36% and peaks near 44% on the wettest days. The odds climb toward the end of the month.

0%10%20%30%40%50%151015202530
Rain chance (%)
127
227
328
428
529
629
730
830
931
1031
1132
1232
1333
1433
1534
1635
1736
1837
1938
2039
2140
2241
2341
2442
2543
2643
2744
2844
2944
3044

Humidity in September

DryComfortableHumidMuggyOppressiveMiserable

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

By dew point, September lands in the humid band about 44% of days. Sticky, muggy-or-worse air turns up on roughly 43% of them.

0%25%50%75%100%151015202530
Dry (%)Comfortable (%)Humid (%)Muggy (%)Oppressive (%)
121552310
221453310
321452320
421452320
521451330
621451330
721450340
811451340
911351350
1011349360
1111349371
1211248381
1311247391
1411246392
1511146412
1611145422
1711143433
1811042433
1911041443
2011040454
2121039455
2221038456
2321037456
2421036457
252935458
262934459
2729334510
2829334511
2929334512
3029324412

Wind in September

Winds average 8 km/h in September.

Across September, daily wind ranges from about 7 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
17calm
27calm
37calm
47calm
58calm
68calm
78calm
88calm
98calm
108calm
118calm
128calm
138calm
148calm
158calm
168calm
178calm
188calm
198calm
208calm
218calm
228calm
238calm
248calm
258calm
268calm
278calm
288calm
298calm
308calm

Sunrise & sunset in September

DaylightNight

Daylight runs from about 11 h 30 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 42 minutes over September. Sunrise moves from 7:05 AM to 6:35 AM, and sunset from 6:37 PM to 6:46 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202530
Daylight (h)Sunrise (AM)Sunset (PM)
111.57:056:37
211.67:046:38
311.67:036:38
411.67:026:38
511.67:016:39
611.67:006:39
711.76:596:39
811.76:586:39
911.76:576:40
1011.76:566:40
1111.86:556:40
1211.86:546:41
1311.86:536:41
1411.86:526:41
1511.86:516:42
1611.96:506:42
1711.96:496:42
1811.96:486:42
1911.96:476:43
2012.06:456:43
2112.06:446:43
2212.06:436:44
2312.06:426:44
2412.16:416:44
2512.16:406:45
2612.16:396:45
2712.16:386:45
2812.16:376:46
2912.26:366:46
3012.26:356:46

Solar energy in September

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in September, about 4.69 kWh/m².

For context, solar energy here swings from a low near 3.42 kWh/m² to a high of 6.06 kWh/m² in February across the year — September's 4.69 kWh/m² falls in the middle.

024151015202530
Solar energy (kWh/m²)Level
14.7Bright
24.7Bright
34.7Bright
44.7Bright
54.7Bright
64.7Bright
74.7Bright
84.7Bright
94.7Bright
104.7Bright
114.7Bright
124.7Bright
134.7Bright
144.7Bright
154.7Bright
164.7Bright
174.7Bright
184.7Bright
194.7Bright
204.7Bright
214.7Bright
224.7Bright
234.7Bright
244.7Bright
254.7Bright
264.7Bright
274.8Bright
284.8Bright
294.8Bright
304.8Bright
Planning a trip in September

Hazard calendar for Itaboraí

In seasonPeak

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

Itaboraí's rainy season runs November–March, 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 Itaboraí?

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

6.5
Sightseeing
5th-best month of the year
6.4
Beach & pool
4th-best month of the year

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

What to pack for Itaboraí in September

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

In September, Itaboraí sees daytime highs around 26°C and nights near 19°C. Worth packing: light clothes, rain gear and sun protection. About 11 days see rain.

light clothesrain gearsun protection

Sea temperature near Itaboraí in September

The nearest coast averages about 21°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 42 km away) is warmest in March at about 25°C and coldest in August near 21°C.

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

20°22°24°26°JanFebMarAprMayJunJulAugSepOctNovDeccoolrefreshingwarmcomfortable to swim
Sea temperature (°C)Comfort
Jan25Warm
Feb25Warm
Mar25Warm
Apr25Warm
May24Refreshing
Jun23Refreshing
Jul22Refreshing
Aug21Refreshing
Sep21Refreshing
Oct22Refreshing
Nov23Refreshing
Dec24Warm

UV index in Itaboraí in September

LowModerateHighVery highExtreme

Clear-sky midday UV in September peaks around 7 — enough to warrant sun protection. The full-year curve, shaded by WHO exposure level, is below.

Under clear skies, the midday UV index in Itaboraí peaks around January 13 at about 14 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near July 13 at about 5 (moderate).

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

025710JanFebMarAprMayJunJulAugSepOctNovDecExtremeVery highHighHighVery highExtremeJan 13UV 14Jul 13UV 5
UV index (midday)Level
Jan14Extreme
Feb13Extreme
Mar12Extreme
Apr9Very high
May7High
Jun6High
Jul5Moderate
Aug8Very high
Sep7High
Oct12Extreme
Nov13Extreme
Dec14Extreme
Location & terrain

Where is Itaboraí?

Itaboraí sits at 22.7°S, 42.9°W, 47 m above sea level, in Brazil. The nearest listed city is Tanguá, 15 km away.

Topography around Itaboraí

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

Within 3 km, the terrain around Itaboraí has only modest variations in elevation — a maximum elevation change of 76 m around an average of 22 m above sea level; within 16 km, large variations in elevation — a maximum elevation change of 741 m; within 80 km, very significant variations in elevation — a maximum elevation change of 2,252 m.

The land around Itaboraí is covered by artificial surfaces (36%), trees (34%) and grassland (29%) within 3 km, grassland (42%) and trees (38%) within 16 km, and trees (42%), water (28%) and grassland (22%) within 80 km.

3 km
76 m
16 km
741 m
80 km
2,252 m
treesgrasslandartificial surfaceswaterwetlandmangroves
September weather nearby: Tanguá 15 km · Maricá 20 km · Magé 21 km · Rio Bonito 26 km · Guapimirim 26 km · Niterói 29 km · São Pedro 37 km · Rio de Janeiro 38 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 Itaboraí (-22.7444°, -42.8594°, elevation 47 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).