SeasonMapIlha Grande weather in September
Brazil
September in Ilha Grande: nice, a little rain, with muggy air — one of the best months to visit.
#2 of 12 months in Ilha Grande · #481 of 1383 destinations to visit in September · comfort 85/100 (tier A)
Updated September 2026 · climate normals from ERA5 reanalysis
Traveller notes on Ilha Grande in September
Other months in Ilha Grande
Ilha Grande's forum calls June the start of the cooler, drier season — less rain than the summer months, but regulars note it's noticeably cooler for the beach than northern Brazil destinations like Salvador if warmth matters more to you than avoiding crowds. Still one of the better months overall, since the rainier stretch has passed.
Add your own note from Ilha Grande's card on the map.
Ilha Grande climate normals — September
| Daytime high | 18°C / 64°F | 😎 nice |
|---|---|---|
| Nighttime low | 14°C / 58°F | |
| Feels like (high) | 18°C / 64°F | |
| Sea temperature | 24°C / 75°F | 🙂 pleasant |
| Rainfall | 76 mm / 3 in | 🌦 some rain |
| Rainy days | 11 days | |
| Humidity | 81% | 💦 very humid |
| Dew point | 12°C / 54°F | |
| Sunshine | 9.5 h/day | |
| Daylight | 12 h | |
| Wind | 14 km/h / 9 mph | |
| Air quality (US AQI) | 76 | 🙂 moderate |
Monthly averages from ERA5 reanalysis. AQI is the mean US Air Quality Index for the month.
Crowds in Ilha Grande in September
How busy the place itself is — school and mass holidays, the months an editor tagged, and how sought-after the weather makes them. Never part of the comfort score.
Busyschool holidays in 2 of the markets that fill it, one of its best months for weather(estimated)
Peak crowdsBusyShoulder seasonQuiet
Best months for Ilha Grande's weather
Ranked by this destination's own climate comfort score across the year — a different thing from how busy it gets (see Crowds above).
Fair weatherIlha Grande's weather doesn't swing hard through the year — comfort stays fairly steady in every month.
Nearby, and something's on
Within 300 km of Ilha Grande — a day trip or a short hop — with something on this month. Never part of the comfort score.
Where is Ilha Grande?
Ilha Grande in September — FAQ
- Is September a good time to visit Ilha Grande?
- September in Ilha Grande: nice, a little rain, with muggy air — one of the best months to visit. It ranks #2 of 12 months for Ilha Grande on SeasonMap's comfort score (85/100).
- What is the weather like in Ilha Grande in September?
- In September, Ilha Grande averages a daily high of 17.8°C and a low of 14.2°C, with about 76 mm of rain over roughly 11.2 rainy days.
- What is the air quality in Ilha Grande in September?
- Ilha Grande has a mean US Air Quality Index of about 76 in September.
Other months in Ilha Grande
Compare Ilha Grande in September
Warmer or cooler than Ilha Grande in September
Similar destinations in South America — September
Within 300 km: Rio de Janeiro's Ipe trees in flower around 15 Aug – 30 Sep, and São Paulo's Ipe trees in flower around 1 Jul – 30 Sep.