Ilhabela weather in September

In September, Ilhabela sees average daytime highs of 21°C and overnight lows near 20°C, with 134 mm of rain across 13.9 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 35% of the time in September, and the air most often feels muggy.

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 Ilhabela's 7th-clearest and 1st-windiest month. For the whole year in context, see Ilhabela's year-round climate.

Daytime high
21°
10th warmest
Overnight low
20°
3rd coldest
Rainfall
134 mm
13.9 wet days
Daylight
11 h 54 min
7:00 AM – 6:52 PM
Cloud cover
58%
7th clearest
Wind
16 km/h
1st windiest
Solar energy
4.53 kWh/m²
Travel score
6.0
out of 10

Ilhabela 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 Ilhabela reaches about 21°C in the afternoon and slips back to 20°C overnight — a 2°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 on par with October.

15°18°20°23°25°151015202530
Avg high (°C)Avg low (°C)
12119
22119
32119
42119
52119
62119
72119
82119
92119
102120
112120
122120
132120
142120
152120
162120
172120
182120
192120
202120
212120
222120
232120
242120
252120
262120
272120
282120
292120
302120

Ilhabela 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
Jan26° / 24°1841613.35.7
Feb26° / 25°13812.512.86.1
Mar26° / 24°17315.312.26.0
Apr24° / 23°11712.611.56.7
May23° / 21°12112.410.96.6
Jun22° / 20°919.810.66.9
Jul21° / 19°102910.76.9
Aug21° / 19°809.411.26.8
Sep21° / 20°13413.911.96.0
Oct22° / 20°1371412.65.9
Nov23° / 21°16215.513.15.8
Dec25° / 23°15414.113.46.1

Cloud cover in September

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 35% of the time in September.

Beyond those clear spells, partly cloudy skies cover about 13% of September, with mostly cloudy or overcast conditions the remaining 52%. Skies tend to cloud over as the month goes on.

0%25%50%75%100%151015202530
Clearer (%)Cloudier (%)
15842
25842
35743
45644
55644
65545
75446
85347
95347
105347
115248
125149
135149
145050
154951
164852
174852
184753
194555
204456
214357
224357
234159
244159
254060
264060
273961
283862
293862
303763

Chance of precipitation in September

Any precipitation

Ilhabela gets around 134 mm of rain over 13.9 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 45% and peaks near 52% on the wettest days. The odds climb toward the end of the month.

0%20%40%60%151015202530
Rain chance (%)
135
235
336
437
537
638
739
839
940
1041
1141
1242
1343
1443
1544
1645
1746
1847
1949
2050
2151
2251
2352
2452
2552
2652
2752
2852
2952
3052

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 45% of days. Sticky, muggy-or-worse air turns up on roughly 46% of them.

0%25%50%75%100%151015202530
Dry (%)Comfortable (%)Humid (%)Muggy (%)Oppressive (%)
141344380
241344390
341343400
441342410
541342420
641341420
731241430
831241430
931241430
1031241441
1131241441
1231141451
1321141451
1421140461
1531140461
1631139471
1731138471
1831138471
1931237471
2031237471
2131236471
2231235472
2341235472
2431234482
2531234483
2631233483
2731233483
2831232484
2931232494
3031232494

Wind in September

Winds average 16 km/h in September, the windiest month of the year.

Across September, daily wind ranges from about 15 km/h on the calmest days to 17 km/h at its breeziest. It stays fairly steady from day to day.

05101520151015202530
Wind speed (km/h)Feels
115light breeze
215light breeze
316light breeze
416light breeze
516light breeze
616light breeze
716light breeze
816light breeze
916light breeze
1016light breeze
1116light breeze
1216light breeze
1316light breeze
1416light breeze
1516light breeze
1616light breeze
1716light breeze
1816light breeze
1916light breeze
2017light breeze
2117light breeze
2217light breeze
2317light breeze
2417light breeze
2517light breeze
2617light breeze
2716light breeze
2816light breeze
2916light breeze
3016light 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 7:16 AM to 6:45 AM, and sunset from 6:47 PM to 6:57 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202530
Daylight (h)Sunrise (AM)Sunset (PM)
111.57:166:47
211.57:156:47
311.67:146:47
411.67:136:48
511.67:126:48
611.67:116:48
711.77:096:49
811.77:086:49
911.77:076:49
1011.77:066:50
1111.77:056:50
1211.87:046:50
1311.87:036:51
1411.87:026:51
1511.87:016:51
1611.97:006:52
1711.96:596:52
1811.96:586:52
1911.96:576:53
2012.06:566:53
2112.06:546:53
2212.06:536:54
2312.06:526:54
2412.16:516:54
2512.16:506:55
2612.16:496:55
2712.16:486:55
2812.16:476:56
2912.26:466:56
3012.26:456:57

Solar energy in September

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in September, about 4.53 kWh/m².

For context, solar energy here swings from a low near 3.25 kWh/m² to a high of 5.95 kWh/m² in December across the year — September's 4.53 kWh/m² falls in the middle.

024151015202530
Solar energy (kWh/m²)Level
14.5Bright
24.5Bright
34.5Bright
44.5Bright
54.5Bright
64.5Bright
74.5Bright
84.5Bright
94.5Bright
104.5Bright
114.5Bright
124.5Bright
134.5Bright
144.5Bright
154.5Bright
164.5Bright
174.5Bright
184.5Bright
194.6Bright
204.6Bright
214.6Bright
224.6Bright
234.6Bright
244.6Bright
254.6Bright
264.6Bright
274.6Bright
284.7Bright
294.7Bright
304.7Bright
Planning a trip in September

Is September a good time to visit Ilhabela?

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

6.0
Sightseeing
8th-best month of the year
3.9
Beach & pool
12th-best month of the year

September is a reasonable time to visit Ilhabela for sightseeing.

What to pack for Ilhabela in September

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

In September, Ilhabela sees daytime highs around 21°C and nights near 20°C. Worth packing: rain gear and sun protection. About 14 days see rain.

rain gearsun protection

Sea temperature near Ilhabela 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 26 km away) is warmest in February at about 27°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°28°JanFebMarAprMayJunJulAugSepOctNovDeccoolrefreshingwarmcomfortable to swim
Sea temperature (°C)Comfort
Jan26Warm
Feb27Warm
Mar26Warm
Apr25Warm
May24Refreshing
Jun22Refreshing
Jul21Refreshing
Aug21Refreshing
Sep21Refreshing
Oct22Refreshing
Nov23Refreshing
Dec25Warm

UV index in Ilhabela in September

LowModerateHighVery highExtreme

Clear-sky midday UV in September peaks around 8 — enough to warrant sun protection. The full-year curve, shaded by WHO exposure level, is below.

Under clear skies, the midday UV index in Ilhabela peaks around January 24 at about 14 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near July 11 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 24UV 14Jul 11UV 5
UV index (midday)Level
Jan14Extreme
Feb14Extreme
Mar11Extreme
Apr9Very high
May7High
Jun6High
Jul5High
Aug8Very high
Sep8Very high
Oct11Extreme
Nov13Extreme
Dec14Extreme
Location & terrain

Where is Ilhabela?

Ilhabela sits at 23.8°S, 45.4°W, 7 m above sea level, in Brazil. The nearest listed city is São Sebastião, 6.0 km away.

Topography around Ilhabela

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

Within 3 km, the terrain around Ilhabela has large variations in elevation — a maximum elevation change of 991 m around an average of 145 m above sea level; within 16 km, very significant variations in elevation — a maximum elevation change of 1,359 m; within 80 km, very significant variations in elevation — a maximum elevation change of 1,647 m.

The land around Ilhabela is covered by water (52%) and trees (41%) within 3 km, trees (50%) and water (45%) within 16 km, and water (54%) and trees (33%) within 80 km.

3 km
991 m
16 km
1,359 m
80 km
1,647 m
treesgrasslandartificial surfaceswater
September weather nearby: São Sebastião 6.0 km · Caraguatatuba 18 km · Ubatuba 48 km · Paraibuna 53 km · Salesópolis 57 km · Biritiba Mirim 73 km · Bertioga 80 km · Guararema 80 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 Ilhabela (-23.7781°, -45.3581°, 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).