São Sebastião in Fall
In fall (March, April and May), São Sebastião sees average daytime highs around 25°C and overnight lows near 21°C, with 481 mm of rain over about 46 wet days across the season. It is the 2nd-warmest season and the 2nd-wettest season.
Over the season highs ease from about 27°C in early March to 23°C by late May. The sky is clear or mostly clear about 31% of the time across fall, and the air most often feels oppressive.
Fall is São Sebastião's 2nd-best season to visit on our travel score. São Sebastião has little temperature swing across the year, so its calendar seasons blur — the season framing matters less here than for a place with four distinct seasons. For the whole year in context, see São Sebastião's year-round climate.
- Avg daytime high
- 25°C
- 2nd-warmest season
- Avg overnight low
- 21°C
- Rainfall
- 481 mm
- 46 wet days
- Avg wind
- 9 km/h
- Travel score
- 5.9
- 2nd-best season
- Months
- Mar · Apr · May
Temperature in São Sebastião in Fall
Over the season highs ease from about 27°C in early March to 23°C by late May.
A typical fall day in São Sebastião reaches about 25°C and drops to 21°C overnight. The warmest of the three months is March, the coolest May.
São Sebastião weather by month
How the three fall months (March, April and May) compare with the rest of the year — the season's months are highlighted.
| Month | High / Low (°C) | Rainfall (mm) | Wet days | Daylight (hours) | Travel score |
|---|---|---|---|---|---|
| Jan | 27° / 24° | 277 | 22.4 | 13.3 | 4.6 |
| Feb | 27° / 24° | 228 | 19.6 | 12.8 | 4.7 |
| Mar | 27° / 23° | 236 | 20.6 | 12.2 | 5.0 |
| Apr | 25° / 22° | 130 | 13.7 | 11.5 | 6.2 |
| May | 23° / 20° | 115 | 12.1 | 10.9 | 6.6 |
| Jun | 23° / 18° | 82 | 9.5 | 10.6 | 7.0 |
| Jul | 22° / 18° | 92 | 8.8 | 10.7 | 7.0 |
| Aug | 22° / 18° | 75 | 8.9 | 11.2 | 7.0 |
| Sep | 22° / 19° | 132 | 13.7 | 11.9 | 6.1 |
| Oct | 23° / 20° | 147 | 15.2 | 12.6 | 5.8 |
| Nov | 24° / 21° | 187 | 17.5 | 13.1 | 5.6 |
| Dec | 26° / 22° | 214 | 19.2 | 13.4 | 5.1 |
Cloud cover in Fall
The sky is clear or mostly clear about 31% of the time across fall.
Chance of precipitation in Fall
São Sebastião gets around 481 mm of rain over 46 wet days across fall. The line is the day-by-day chance of measurable precipitation.
Humidity in Fall
Most of fall feels oppressive — the stacked bands show each day's mix of comfort levels, read off the dew point.
Wind in Fall
Winds average 9 km/h across fall.
Sunrise & sunset in Fall
Daylight runs from about 12 h 30 min in early March to 10 h 42 min by late May. The lit band spans sunrise to sunset each day.
Solar energy in Fall
Average shortwave solar energy reaching the ground each day across fall, about 4.3 kWh/m².
Is fall a good time to visit São Sebastião?
Our two travel scores rate fall for general sightseeing and for beach or pool weather — 0 (poor) to 10 (ideal), averaged across the three months.
fall is a reasonable time to visit São Sebastião for sightseeing.
What to pack for São Sebastião in Fall
From fall's temperature range, rain chance, sun and wind — what's worth putting in the bag.
In fall, São Sebastião sees daytime highs around 25°C and nights near 21°C. Pack rain gear. Worth having: light clothes and sun protection. About 46 days see rain.
Sea temperature near São Sebastião in Fall
The nearest coast averages about 25°C across fall — the other half of the beach question. The full-year curve and swim-comfort zones are below.
The sea at the nearest coast (about 25 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.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Sea temperature (°C) | 26 | 27 | 27 | 26 | 24 | 22 | 21 | 21 | 21 | 22 | 23 | 25 |
| Comfort | Warm | Warm | Warm | Warm | Refreshing | Refreshing | Refreshing | Refreshing | Refreshing | Refreshing | Refreshing | Warm |
| Sea temperature (°C) | Comfort | |
|---|---|---|
| Jan | 26 | Warm |
| Feb | 27 | Warm |
| Mar | 27 | Warm |
| Apr | 26 | Warm |
| May | 24 | Refreshing |
| Jun | 22 | Refreshing |
| Jul | 21 | Refreshing |
| Aug | 21 | Refreshing |
| Sep | 21 | Refreshing |
| Oct | 22 | Refreshing |
| Nov | 23 | Refreshing |
| Dec | 25 | Warm |
UV index in São Sebastião in Fall
Clear-sky midday UV across fall averages around 9 (very high — sun protection essential). The full-year curve, shaded by WHO exposure level, is below.
Under clear skies, the midday UV index in São Sebastião peaks around February 8 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.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| UV index (midday) | 14 | 14 | 11 | 9 | 7 | 6 | 5 | 8 | 8 | 11 | 13 | 14 |
| Level | Extreme | Extreme | Extreme | Very high | High | High | High | Very high | Very high | Extreme | Extreme | Extreme |
| UV index (midday) | Level | |
|---|---|---|
| Jan | 14 | Extreme |
| Feb | 14 | Extreme |
| Mar | 11 | Extreme |
| Apr | 9 | Very high |
| May | 7 | High |
| Jun | 6 | High |
| Jul | 5 | High |
| Aug | 8 | Very high |
| Sep | 8 | Very high |
| Oct | 11 | Extreme |
| Nov | 13 | Extreme |
| Dec | 14 | Extreme |
Air quality in São Sebastião in Fall
Average fine-particle pollution (PM2.5) through the year — so you can see where fall falls, not just the annual average.
Air quality in São Sebastião is worst in June — around 23 µg/m³ PM2.5 (moderate), about 1.8× the cleanest month (November, 13 µg/m³).
Modeled monthly averages (CAMS reanalysis, 2015–2024).
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| PM2.5 (µg/m³) | 13 | 13 | 13 | 14 | 18 | 23 | 23 | 22 | 21 | 16 | 13 | 13 |
| Level | Moderate | Moderate | Moderate | Moderate | Moderate | Moderate | Moderate | Moderate | Moderate | Moderate | Moderate | Moderate |
| PM2.5 (µg/m³) | Level | |
|---|---|---|
| Jan | 13 | Moderate |
| Feb | 13 | Moderate |
| Mar | 13 | Moderate |
| Apr | 14 | Moderate |
| May | 18 | Moderate |
| Jun | 23 | Moderate |
| Jul | 23 | Moderate |
| Aug | 22 | Moderate |
| Sep | 21 | Moderate |
| Oct | 16 | Moderate |
| Nov | 13 | Moderate |
| Dec | 13 | Moderate |
Where is São Sebastião?
São Sebastião sits at 23.8°S, 45.4°W, 6 m above sea level, in Brazil. The nearest listed city is Ilhabela, 6.0 km away.
Topography around São Sebastião
How much the land rises and falls, and what covers it, within 3, 16 and 80 km of São Sebastião.
Within 3 km, the terrain around São Sebastião has large variations in elevation — a maximum elevation change of 806 m around an average of 181 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 São Sebastião is covered by trees (50%) and water (39%) within 3 km, trees (53%) and water (36%) within 16 km, and water (53%) and trees (33%) within 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
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 São Sebastião (-23.76°, -45.4097°, elevation 6 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.