SeasonMapIlha Grande weather in December
Brazil
December in Ilha Grande: nice, soaked, with muggy air — fine if you can take 22 rainy days.
#11 of 12 months in Ilha Grande · #540 of 1383 destinations to visit in December · comfort 77/100 (tier B)
Updated September 2026 · climate normals from ERA5 reanalysis
Traveller notes on Ilha Grande in December
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 — December
| Daytime high | 20°C / 68°F | 😎 nice |
|---|---|---|
| Nighttime low | 17°C / 63°F | |
| Feels like (high) | 22°C / 72°F | |
| Sea temperature | 27°C / 80°F | 😎 warm sea |
| Rainfall | 229 mm / 9 in | ⛈ soaked |
| Rainy days | 22 days | |
| Humidity | 84% | 💦 very humid |
| Dew point | 16°C / 60°F | |
| Sunshine | 10.2 h/day | |
| Daylight | 13.5 h | |
| Wind | 12 km/h / 8 mph | |
| Air quality (US AQI) | 56 | 🙂 moderate |
Monthly averages from ERA5 reanalysis. AQI is the mean US Air Quality Index for the month.
Crowds in Ilha Grande in December
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.
Peak crowdstravelers describe it as peak season, Southern summer peak, Summer holidays in Brazil
Sourced from traveler notes: “…e back half of the month. Posters flag December as Brazil's high season, so booking accommodation well ahead is standard advice giv…” — Tripadvisor community
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.
What's on in Ilha Grande in December
Recurring seasonal events, natural spectacles, closures and holidays — curated and sourced.
- Season
Sea warm enough to swim
1 Dec – 30 Apr · usuallyThe water on the Angra side is comfortable without a wetsuit from December to April, which is also when the visibility is worst after a storm. Late March is the sweet spot.
- Season
Summer storms and mud
1 Dec – 31 Mar · usuallyMonsoonRiskClosuresAfternoon storms come off the Serra do Mar most days, the forest trails turn to mud and the steep ones close after heavy rain. This coast has a history of landslides in the worst weeks.
- Season
Southern summer peak
26 Dec – 28 FebSchool holidaysCrowdedBook earlyBetween the new year and carnival the boats from Angra and Conceicao run full, Abraao's few hundred beds go early and the trail to Lopes Mendes is a procession. Nothing on the island is quick.
- Season
Wet season
MonsoonRisk22 rainy days and about 229 mm in the month — the real kind of rainy season, not afternoon showers.
from the climate normals
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 December — FAQ
- Is December a good time to visit Ilha Grande?
- December in Ilha Grande: nice, soaked, with muggy air — fine if you can take 22 rainy days. It ranks #11 of 12 months for Ilha Grande on SeasonMap's comfort score (77/100).
- What is the weather like in Ilha Grande in December?
- In December, Ilha Grande averages a daily high of 19.8°C and a low of 17°C, with about 228.6 mm of rain over roughly 22.2 rainy days.
- What is the air quality in Ilha Grande in December?
- Ilha Grande has a mean US Air Quality Index of about 56 in December.
Other months in Ilha Grande
Compare Ilha Grande in December
Warmer or cooler than Ilha Grande in December
Similar destinations in South America — December
Within 300 km: Rio de Janeiro's Reveillon on Copacabana on 30 Dec – 1 Jan.