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
The best time to visit Ilha Grande is from May to August. The most comfortable month is July, with highs of 26 °C (79 °F) and 41 mm of rain over 6 days. January is the rainiest month (190 mm over 18 days), and the summer peak is the high season, with higher prices and big crowds.
Source: INMET (updated 2026)
When to go
Best time to visit, month by month
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec
Best window: May to August More rain / less comfortable Comfort index · INMET (updated 2026)
Ilha Grande month by month
Temperature and rainfall averages from INMET (updated 2026). The verdict combines thermal comfort and rainfall. Tap a month to see the weather, crowds, prices and what is going on in detail.
| Month | High / Low | Rain | Rainy days | Verdict |
|---|---|---|---|---|
| January | 31° / 24° | 190 mm | 18 | Best avoided |
| February | 32° / 24° | 168 mm | 15 | Best avoided |
| March | 31° / 23° | 150 mm | 15 | Best avoided |
| April | 29° / 22° | 98 mm | 11 | Fair |
| May | 27° / 20° | 62 mm | 8 | Good |
| June | 26° / 18° | 45 mm | 6 | Good |
| July ★ | 26° / 18° | 41 mm | 6 | Good |
| August | 27° / 18° | 43 mm | 6 | Good |
| September | 27° / 19° | 75 mm | 10 | Good |
| October | 28° / 21° | 105 mm | 13 | Fair |
| November | 29° / 22° | 148 mm | 15 | Fair |
| December | 30° / 23° | 180 mm | 17 | Best avoided |
Best month
July
Driest month
July
Avoid (more rain)
January
Tours and tickets
Things to do in Ilha Grande
Where to stay
Hotels in Ilha Grande
July is the best month and also falls in the high season in Ilha Grande: the top-rated hotels fill up and rates rise close to the date. Book your room as soon as you have settled on your dates.
Rates change with the dates: confirm the price on Booking.com.
The weather in Ilha Grande throughout the year
The May to August window brings together the most comfortable months in Ilha Grande: less rain and pleasant temperatures. July is usually the best month, with highs of 26 °C (79 °F), lows of 18 °C (64 °F) and only about 6 days of rain in the month: good conditions for enjoying outdoor attractions with less risk of downpours.
Summer. In summer (December to February), Ilha Grande has highs of around 31 °C (88 °F) and lows of 24 °C (75 °F), and it is the wetter season, with about 179 mm of rain spread over about 17 days a month. The days are hot and call for beach time and shade.
Fall. In fall (March to May), Ilha Grande has highs of around 29 °C (84 °F) and lows of 22 °C (72 °F), and it is the wetter season, with about 103 mm of rain spread over about 11 days a month. The days are hot and call for beach time and shade.
Winter. In winter (June to August), Ilha Grande has highs of around 26 °C (79 °F) and lows of 18 °C (64 °F), and it is the driest time of year, with about 43 mm of rain a month. Temperatures are pleasant for sightseeing all day.
Spring. In spring (September to November), Ilha Grande has highs of around 28 °C (82 °F) and lows of 21 °C (70 °F), and it is the wetter season, with about 109 mm of rain spread over about 13 days a month. The days are hot and call for beach time and shade.
What to avoid
There are two periods to think twice about before booking. January is usually the rainiest month, so anyone who prioritizes sun should avoid it. The other is high season (New Year's Eve, Carnival and the July school break), when attractions fill up and prices rise; if you want peace and savings, choose weeks without public holidays. None of this rules out the trip, but it changes the experience and the cost quite a bit.
If you are torn between the island and the Lakes Region, you will find the answer in Arraial do Cabo or Ilha Grande, with the cost of the boat crossing included.