8· 1 review
São Sebastião Whale Watching
São Sebastião offers one of the best spots in Brazil to see humpback whales, making this crossing a must for anyone visiting the region.
4 h
from US$ 102
Short answer
In September, São Sebastião averages highs of 25 °C (77 °F) and lows of 16 °C (61 °F), with about 197 mm of rain spread over roughly 13 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
25 / 16 °C
high / low
Rain
197 mm
13 days
Daylight
11h58
sunset at 17:55
Crowds
Moderate
1 public holiday
What to expect in São Sebastião in September
Editor's tip
September is spring in São Sebastião. In Brazil the seasons are the reverse of those in the Northern Hemisphere. Temperatures are pleasant, with highs of 25 °C (77 °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. It rains fairly often, so keep an indoor plan handy for gray days.
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 · ~R$ 412
Moderate prices outside public holidays, which push rates and crowds up. The average nightly rate for lodging in São Sebastião is around R$ 412 (Brazilian reais), depending on the date.
Tours and tickets
Things to do in São Sebastião in September
Where to stay
Hotels in São Sebastião
In September, demand in São Sebastião 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 jacket for the evening · nights of 16 °C (61 °F) Light clothing for the day · highs of 25 °C (77 °F) Rain jacket or umbrella · 13 days of rain in the month Sunscreen and sunglasses · strong sun on the tours Quick-dry clothing · humidity of 85% 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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