8· 1 review
Acaiá Cave & Ilha Grande Lagoons Boat Tour
If you're in Ilha Grande, don't miss the opportunity to take a tour around the Acaiá Cave and its main lagoons. You'll fall in love with its landscapes!
7 h
from US$ 46
Short answer
In September, Ilha Grande averages highs of 27 °C (81 °F) and lows of 19 °C (66 °F), with about 75 mm of rain spread over roughly 10 days. September is one of the rainiest months of the year, so bring a rain jacket and keep some indoor activities in mind. Crowds tend to be moderate this month.
Climate · INMET (updated 2026)
Temperature
27 / 19 °C
high / low
Rain
75 mm
10 days
Daylight
11h58
sunset at 17:50
Crowds
Moderate
1 public holiday
What to expect in Ilha Grande in September
Editor's tip
September is spring in Ilha Grande. In Brazil the seasons are the reverse of those in the Northern Hemisphere. Temperatures are pleasant, with highs of 27 °C (81 °F) and nights that still call for a light jacket. Crowds sit somewhere in the middle, with peaks on public holidays. Outside those dates, you can enjoy the place at an easy pace and spend less. Rain, when it comes, is usually brief and does not spoil the day.
Myllena Vieira · Editor at VisiteCrowds
Crowd level: moderate
Moderate crowds, with peaks on public holidays. Outside those dates, you can enjoy the place at a calmer pace.
Prices
Rates: moderate
Moderate prices outside public holidays, which push rates and crowds up.
Tours and tickets
Things to do in Ilha Grande in September
Where to stay
Hotels in Ilha Grande
In September, demand in Ilha Grande is moderate: most hotels have room, but public holidays fill them up. Compare rates and book a few weeks ahead.
Rates change with the dates: confirm the price on Booking.com.
What happens in September
No major fixed festivals in September, but public holidays (Independence Day) bring more people to the destination.
Public holidays in September: Independence Day (07/09). Expect more people and higher prices around these dates.
What to pack in September
Light clothing for the day · highs of 27 °C (81 °F) Rain jacket or umbrella · 10 days of rain in the month Sunscreen and sunglasses · strong sun on the tours Quick-dry clothing · humidity of 80% Comfortable walking shoes · you will be on foot much of the day
Looking for better weather?
Where the weather is good in September
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