Itanhaém weather in September

In September, Itanhaém sees average daytime highs of 21°C and overnight lows near 19°C, with 141 mm of rain across 14.2 wet days and about 11.9 hours of daylight. It is the 10th-warmest and 7th-wettest month of the year here.

Day-to-day highs hold fairly steady near 21°C through the month. The sky is clear or mostly clear about 25% 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 Itanhaém's 8th-clearest and 3rd-windiest month. For the whole year in context, see Itanhaém's year-round climate.

Daytime high
21°
10th warmest
Overnight low
19°
4th coldest
Rainfall
141 mm
14.2 wet days
Daylight
11 h 54 min
7:06 AM – 6:57 PM
Cloud cover
66%
8th clearest
Wind
13 km/h
3rd windiest
Solar energy
4.3 kWh/m²
Travel score
5.8
out of 10

Itanhaém 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 21°C through the month.

A typical September day in Itanhaém reaches about 21°C in the afternoon and slips back to 19°C overnight — a 3°C spread between the day's warmth and the night's chill. On most days the high lands between 19°C and 24°C. Set against its neighbours, September runs on par with August and about 1°C cooler than October.

15°18°20°23°25°151015202530
Avg high (°C)Avg low (°C)
12118
22118
32118
42118
52118
62118
72118
82118
92118
102118
112119
122219
132219
142219
152219
162219
172219
182219
192219
202219
212219
222219
232219
242219
252219
262219
272219
282219
292219
302219

Itanhaém weather by month

How September compares with the rest of the year at a glance. September is the 10th-warmest and 7th-wettest month here — the current month is highlighted below.

MonthHigh / Low (°C)Rainfall (mm)Wet daysDaylight (hours)Travel score
Jan27° / 24°22722.913.34.6
Feb27° / 24°21119.712.84.7
Mar26° / 23°21221.712.25.0
Apr25° / 22°13714.611.56.2
May23° / 20°12513.510.86.4
Jun22° / 18°10110.410.56.6
Jul21° / 17°10710.410.76.6
Aug21° / 18°8810.111.26.5
Sep21° / 19°14114.211.95.8
Oct23° / 20°15516.712.65.5
Nov24° / 21°1631713.25.6
Dec25° / 23°17419.213.55.2

Cloud cover in September

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 25% 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 61%. Skies tend to cloud over as the month goes on.

0%25%50%75%100%151015202530
Clearer (%)Cloudier (%)
15248
25149
35149
45050
54951
64753
74654
84555
94456
104456
114357
124159
134060
144060
153961
163862
173763
183763
193565
203565
213367
223367
233268
243268
253268
263169
273169
283070
293070
302971

Chance of precipitation in September

Any precipitation

Itanhaém gets around 141 mm of rain over 14.2 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 47% and peaks near 56% on the wettest days. The odds climb toward the end of the month.

0%20%40%60%151015202530
Rain chance (%)
138
238
339
439
540
640
741
841
942
1042
1143
1243
1343
1444
1545
1646
1747
1848
1949
2050
2151
2252
2352
2453
2554
2655
2755
2856
2956
3056

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 38% of them.

0%25%50%75%100%151015202530
Dry (%)Comfortable (%)Humid (%)Muggy (%)Oppressive (%)
161452280
261451290
361450300
451450310
551449320
651448330
751448330
841448340
941448340
1041447340
1141447350
1231447350
1331447360
1431446370
1531445371
1631445371
1741444381
1841443381
1941442381
2041442381
2141441391
2241441391
2341440401
2441439402
2541439412
2641438422
2741338432
2841337433
2941337443
3041336443

Wind in September

Winds average 13 km/h in September.

Across September, daily wind ranges from about 12 km/h on the calmest days to 13 km/h at its breeziest. It stays fairly steady from day to day.

05101520151015202530
Wind speed (km/h)Feels
112calm
212calm
312calm
412calm
512calm
612light breeze
712light breeze
812light breeze
912light breeze
1012light breeze
1112light breeze
1212light breeze
1313light breeze
1413light breeze
1513light breeze
1613light breeze
1713light breeze
1813light breeze
1913light breeze
2013light breeze
2113light breeze
2213light breeze
2313light breeze
2413light breeze
2513light breeze
2613light breeze
2713light breeze
2813light breeze
2913light breeze
3013light breeze

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 7:22 AM to 6:50 AM, and sunset from 6:52 PM to 7:02 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202530
Daylight (h)Sunrise (AM)Sunset (PM)
111.57:226:52
211.57:216:52
311.67:206:53
411.67:196:53
511.67:186:53
611.67:166:54
711.67:156:54
811.77:146:55
911.77:136:55
1011.77:126:55
1111.77:116:56
1211.87:106:56
1311.87:096:56
1411.87:086:57
1511.87:076:57
1611.97:066:57
1711.97:056:58
1811.97:036:58
1911.97:026:58
2012.07:016:59
2112.07:006:59
2212.06:596:59
2312.06:587:00
2412.16:577:00
2512.16:567:01
2612.16:557:01
2712.16:547:01
2812.26:537:02
2912.26:527:02
3012.26:507:02

Solar energy in September

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in September, about 4.3 kWh/m².

For context, solar energy here swings from a low near 3.03 kWh/m² to a high of 5.89 kWh/m² in December across the year — September's 4.3 kWh/m² falls in the middle.

012345151015202530
Solar energy (kWh/m²)Level
14.2Bright
24.2Bright
34.2Bright
44.3Bright
54.3Bright
64.3Bright
74.3Bright
84.3Bright
94.3Bright
104.3Bright
114.3Bright
124.3Bright
134.3Bright
144.3Bright
154.3Bright
164.3Bright
174.3Bright
184.3Bright
194.3Bright
204.3Bright
214.3Bright
224.3Bright
234.4Bright
244.4Bright
254.4Bright
264.4Bright
274.4Bright
284.4Bright
294.5Bright
304.5Bright
Planning a trip in September

Is September a good time to visit Itanhaém?

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

5.8
Sightseeing
6th-best month of the year
3.8
Beach & pool
12th-best month of the year

September is a reasonable time to visit Itanhaém for sightseeing.

What to pack for Itanhaém in September

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

In September, Itanhaém sees daytime highs around 21°C and nights near 19°C. Pack rain gear. About 14 days see rain.

rain gear

Sea temperature near Itanhaém 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 18 km away) is warmest in February at about 27°C and coldest in August near 20°C.

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

20°25°JanFebMarAprMayJunJulAugSepOctNovDeccoolrefreshingwarmtropicalcomfortable to swim
Sea temperature (°C)Comfort
Jan27Warm
Feb27Warm
Mar27Warm
Apr26Warm
May24Refreshing
Jun22Refreshing
Jul21Refreshing
Aug20Refreshing
Sep21Refreshing
Oct22Refreshing
Nov23Refreshing
Dec25Warm

UV index in Itanhaém 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 Itanhaém peaks around January 23 at about 14 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near July 12 at about 5 (high).

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

025710JanFebMarAprMayJunJulAugSepOctNovDecExtremeVery highHighVery highExtremeJan 23UV 14Jul 12UV 5
UV index (midday)Level
Jan14Extreme
Feb14Extreme
Mar9Very high
Apr8Very high
May7High
Jun6High
Jul5Moderate
Aug7High
Sep7Very high
Oct10Extreme
Nov13Extreme
Dec13Extreme

Air quality in Itanhaém 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 Itanhaém is worst in July — around 52 µg/m³ PM2.5 (poor), about 2.1× the cleanest month (February, 24 µg/m³).

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

0204060JanFebMarAprMayJunJulAugSepOctNovDecModeratePoorModerateJul 1451 µg/m³Feb 1225 µg/m³
PM2.5 (µg/m³)Level
Jan25Moderate
Feb24Moderate
Mar26Moderate
Apr28Moderate
May36Poor
Jun49Poor
Jul52Poor
Aug47Poor
Sep41Poor
Oct31Moderate
Nov25Moderate
Dec26Moderate
Location & terrain

Where is Itanhaém?

Itanhaém sits at 24.2°S, 46.8°W, 12 m above sea level, in Brazil. The nearest listed city is Mongaguá, 20 km away.

Topography around Itanhaém

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

Within 3 km, the terrain around Itanhaém has only modest variations in elevation — a maximum elevation change of 70 m around an average of 3 m above sea level; within 16 km, large variations in elevation — a maximum elevation change of 700 m; within 80 km, very significant variations in elevation — a maximum elevation change of 1,389 m.

The land around Itanhaém is covered by water (43%) and artificial surfaces (29%) within 3 km, water (48%) and trees (44%) within 16 km, and trees (47%) and water (41%) within 80 km.

3 km
70 m
16 km
700 m
80 km
1,389 m
treesgrasslandartificial surfacesbare terrainwaterwetlandmangroves
September weather nearby: Mongaguá 20 km · Peruíbe 26 km · Embu-Guaçu 39 km · Juquitiba 40 km · São Lourenço da Serra 40 km · Parelheiros 40 km · Itariri 41 km · Praia Grande 44 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 Itanhaém (-24.1831°, -46.7889°, elevation 12 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. 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).